NZ245300A - Protecting organs from ischemic damage using 4-(cyanoguanidine)benzopyran derivatives - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £45300 New Zealand No. 245300 International No. PCT/ TO BE ENTERED AFTER ACCEPTANCE AND PUBLICATION Priority dates: Complete Specification Filed: 28.02.1992 Classification:^) A61K31/35,44 Publication date: 24 July 1997 Journal No.: 1418 NO DRAWINGS NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention: PYRANYL CYANOGUANIDINE DERIVATIVES Name, address and nationality of applicant(s) as in international application form: E R SQUIBB & SONS INC, a Delaware corporation of Lawrenceville Princeton Road, Princeton, New Jersey, United States of America 24 5 3 0 0 Under the provisions at Regulation 23 (1) the Specific**-'*' h 19^-—• 27 NOV 1992 Received Initwls NO DRAWINGS NEW ZEALAND PATENTS ACT, 1953 No.

DIV OF 233 845 Date: 28 February 1992 (filed 29 May 1990) COMPLETE SPECIFICATION vpyranyl cyanoguanidine derivatives" K/We, e R SQUIBB & SONS INC, a corporation of Delaware, United States of America, having its offices at Lawrenceville-Princeton Road, Princeton, New Jersey, United States of America.

A h'ireby declare the invention for which £x/ we pray that a patent may be granted to RXSQtus, and the method by which it is to be performed, to be particularly described in and by the following statement: - - 1 - (followed by page la) 245 30 0 -ICv- Field of -the Invention The present invention relates to the use of an organ-protecting amount of a compound in the manufacture of a medicament to protect an organ from ischemic damage and to a novel solution.

Summary of the Invention In accordance with the present invention there is provided the use of an organ protecting amount of a compound of the formula wherein a, b, and c are all carbons or one of a, and c can be nitrogen or -NO- and the others are carbons; 245300 HA488b is R7 R8 >NCN or R^ ( > NCN; 'n ■N I R2 is hydrogen, hydroxy, -0CCH3; O R3 and R4 are each independently hydrogen, alkyl or arylalkyl, or, R3 and R4 taken together with the carbon atom to which they are attached form a 5- to 7-membered carbocyclic ring; R5 is selected from H, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, arylalkyl, cycloalkylalkyl, -CN, -N02, -COR, -COOR, -CONHR, -CONR2, -CF3, S-alkyl, -SOalkyl, -S02alkyl, O OO ll II / -P(0- alkyl )2,-P^ O—H R, halogen, amino, ) substituted amino, O-alkyl, OCF3, OCH2CF3/ -OCOalkyl, -OCONRalkyl, -NRCOalkyl and NRCOOalkyl, NRC0NR2 wherein R in each of the above groups can be hydrogen, alkyl, aryl, arylalkyl, cycloalkyl, or (cycloalkyl)alkyl; R6 is selected from H, alkyl, OH, O-alkyl, amino, substituted amino, CN, and N02; R7 and R8 are each independently selected from hydrogen, alkyl, alkenyl, aryl, (heterocyclo)alkyl, heterocyclo, arylalkyl, cycloalkyl and (cycloalkyl)alkyl, substituted alkyl wherein the substituents include alkoxy, alkylthio and substituted amino, or R7 and Rs taken together with the nitrogen atom to which they are attached form 1-pyrrolidinyl, 1-piperidinyl, 1-azepinyl, 4-morpholinyl, 4-thiamorphilinyi, 1-piperazinyl, HA488b 2^5Jon 4-alkyl-l-piperazinyl or 4-arylalkyl-l-piperazinyl, wherein each of the so-formed groups can be substituted with alkyl, alkoxy, alkylthio, halogen or trifluoromethyl; R9 and R10 are selected from hydrogen, alkyl, alkenyl, aryl, arylalkyl, cycloalkyl or cycloalkylalkyl; and n is 1, 2 or 3^ ip the manufacture of a medicament for protecting an organ from ischemic damage in a mammalian species.

Detailed Description of "the Present Invention This invention in its broadest aspects relates to the cyanoguanidine compounds of formula I above, to compositions and the use of such compounds in the manufacture of medicaments. The compounds of formula I are useful, for example, as cardiovascular agents.

Preferred compounds are those with the 3S, 4R stereochemistry.

It has been found that the present compounds are useful for preventing or alleviating 20 ischemic damage which results from organ surgery procedures, e.g., bypass and transplant.

The term "alkyl" used in defining various symbols refers to straight or branched chain saturated hydrocarbon radicals having up to eight 25 carbons, preferably from one to five carbons.

Similarly, the terms "alkoxy" and "alkylthio" refer to such alkyl groups attached to an oxygen or sulfur. _ The term "alkenyl" refers to straight or 30 branched chain hydrocarbon radicals having from two to eight carbons and one double bond, preferably three to five carbons. The term "alkynvl" refers to straight or branched chain hydrocarbon radicals having from two to eight carbons and one triple bond, preferably three to five carbons.

The term "cycloalkyl" refers to saturated carbocyclic rings of 3 to 7 carbon atoms with cyclopropyl, cvclopentvl and cyclohexyl being most., preferred. ^ ^ » A 245300 HA488b The term "halo" or "halogen" refers to chloro, bromo and fluoro.

The term "halo substituted alkyl" refers to such alkyl groups described above in which one or more hydrogens have been replaced by chloro, bromo or fluoro groups such as trifluoromethyl, which is preferred,pentafluoroethyl, 2,2,2-trichloroethyl, chloromethyl, bromomethyl, etc.

The term "aryl" refers to phenyl, 1-naphthyl, 2-naphthyl or mono substituted phenyl, 1-naphthyl, 2-naphthyl wherein said substituent is alkyl of 1 to 4 carbons, alkylthio of 1 to 4 carbons, alkoxy of 1 to 4 carbons, halo, nitro, cyano, hydroxy, amino, -NH-alkyl wherein alkyl is of 1 to 4 carbons, -N(alkyl)2 wherein alkyl is of 1 to 4 carbons, alkyl of 1 to 4 carbons, alkoxy of 1 to 4 carbons, alkylthio of 1 to 4 carbons, halo, hydroxy or CF3), -0-CH2-cycloalkyl, or -S-CH2- cycloalkyl, and di-substituted phenyl, 1-naphthyl, 2-naphthyl wherein said substituents are selected from methyl, methoxy, methylthio, halo, CF3, nitro, amino, and Preferred aryl groups include unsubstituted phenyl and monosubstituted phenyl wherein the substituents are nitro, halo, -CF3, alkyl, cyano or methoxy.

R (wherein Rji is hydrogen, OCHF2. 24 5 30 0 HA488b The term "heterocyclo" refers to fully saturated or unsaturated rings of 5 or 6 atoms containing one or two O and s atoms and/or one to four N atoms provided that the total number of 5 hetero atoms in the ring is 4 or less. The hetero ring is attached by way of an available carbon atom. Preferred monocyclic hetero groups include 2- and 3-thienyl, 2- and 3-furyl, 2-, 3- and 4-pyridyl, and imidazolyl. The term hetero also 10 includes bicyclic rings wherein the five or six membered ring containing 0, S and N atoms as defined above is fused to a benzene ring and the bicyclic ring is attached by way of an available carbon atom. Preferred bicyclic hetero groups 15 include 4, 5, 6, or 7-indolyl, 4, 5, 6, or 7-isoindolyl, 5, 6, 7 or 8-guinolinyl, 5, 6, 7 or 8-isoquinolinyl, 4, 5, 6, or 7-benzothiazolyl, 4, , 6 or 7-benzoxazolyl, 4, 5, 6 or 7-benzimidazolyl, 4, 5, 6 or 7-benzoxadiazolyl, and 4, 5, 6 or 20 7-benzofuranzanyl.

The term heterocyclo also includes such monocyclic and bicyclic rings wherein an available carbon atom is substituted with a lower alkyl of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, 25 lower alkoxy of 1 to 4 carbons, halo, nitro, keto, cyano, hydroxy, amino, -NH-alkyl wherein alkyl is of 1 to 4 carbons, -N(alkyl)2 wherein alkyl is of 1 to 4 carbons, CF3, or OCHF2 or such monocyclic and bicyclic rings wherein two or three available 30 carbons have substituents selected from methyl, methoxy, methylthio, halo, CF3, nitro, hydroxy, amino and OCHF2. 24 5 3 0 0 HA488b The term "substituted amino" refers to a group of the formula -NZ,Z2 wherein Zi is hydrogen, alkyl, cycloalkyl, aryl, arylalkyl, cycloalkylalkyl and Z2 is alkyl, cycloalkyl, aryl, arylalkyl, cycloalkylalkyl or Zj and Z2 taken together with the nitrogen atom to which they are attached are 1-pyrrolidinyl, 1-piperidinyl, 1-azepinyl, 4-morpholinyl, 4-thiamorpholinyl, 1-piperazinyl, 4-alkyl-l-piperazinyl, 4-arylalkyl-l-piperazinyl, 4-diarylalkyl-l-piperazinyl, 1-pyrrolidinyl, 1-piperidinyl, or 1-azepinyl substituted with alkyl, • alkoxy, alkylthio, halo, trifluoromethyl or hydroxy.

The compounds .of formula I wherein R2 is can be prepared by treatment of a thiourea of the formula R? Rs R9-N II H with an amine of the formula 245300 HA488b III in the presence of a carbodiimide, preferably 10 l-(3-dimethylaminopropyl)-3-ethylcarbodiimide or dicyclohexylcarbodiimide and an acid source in an organic solvent, such as dimethylformamide, tetrahydrofuran, acet&nitrile or dichloromethane.

The thiourea of formula II, wherein R8 is 15 hydrogen can be prepared by heating an isothiocyanate of the formula IV R7N=C=S with either monosodixim cyanamide or with cyanamide in the presence of an organic case, such as triethyl amine.

The other thioureas of formula II can be prepared by standard methods described in the 25 literature, such as by C. R. Rasmussen, F. J.

Villani, Jr., L. E; Weaner, B. E. Reynolds, A. R.

Hood, L. R. Hecker, S. O. Nortey, A. Hanslin, M. J. Costanzo, E. T. Powell, A. J. Molinari, Synthesis, 1988, p. 456, and V. V. Mozolis and S. P. Locubaitite, 30 Russian Chemical Reviews, 1973, 42, 587.

The aminoalcohol of formula III wherein R2 is hydroxy can be prepared by methods described in the literature, such as by J. M. Evans, C. S. Fake, 24 5 3 HA488b T. C. Hamilton, R. H. Poyser, E. A. Watts, J. Med. Chem. 1983, 26, 1582 and J. Med. Chem. 1986, 29, 2194; R. W. Lang, P. F. Wenk, Helvetica Chimica Acta, 1988, 71, 596; EP 0205292 A2 (1986), and WO 87/07607.

The amine of formula III, wherein R2 is hydrogen, can be prepared from a ketone of the formula by standard methodology. The ketone of formula V can be obtained by literature procedures, such as disclosed by P. Sebok and T. Timar, Heterocycles, 1988, 27, 2595; P. Teixidor et al., Heterocycles, 1988, 27, 2459; A. Benerji and N. C. Goomer, Tetrahedron Letters, 1979, 3685; G. Ariamala and K. K. Subramanian, Tetrahedron Letters, Vol. 29, No. 28, p. 3487-3488 (1988).

The compounds of formula I wherein Rj is R7 Rs \=NCN can also be prepared by heating a thiourea R9V of the formula 245300 HA488b VI He Rs R2 r3 with monosodium cyanamide in the presence of a carbodiimide such as l-(3-dimethylaminopropyl)-3-ethylcarbodiimide or dicyclohexylcarbodiimide in an organic solvent-.

The compounds of formula VI can be prepared from the amino alcohol of formula III by standard methods (i.e., the Rasmussen and Mozolis references above).

ICN can also be prepared by reacting a R " I compound of the formula The compounds of formula I wherein Ri is R9-N VII 245300 HA488b with an amine of the formula VIII r7r8nh in a polar solvent such as isopropanol. The compounds of formula VII are prepared by reacting an amine of formula III with diphenylcyanocarbon-imidate.

The compounds of formula I wherein Ri is Rs / Ri o ( -N >=NCN can be prepared by treating a 'n ■N compound of the formula R8 ,NCN K SCH? IX with mercuric acetate in an alcoholic solvent such as methanol.

The compounds of formula IX are prepared by treating a diamine of the formula 2 4 5 3 0 0 HA488b with dimethyl-N-cyanodithioiminocarbonate.

The compounds of formula I wherein R! is / *8 ( )=NCN can also be prepared by treating a n diamine of formula X with diphenylcyanocarbon-imidate in an alcoholic solvent, such as 2-propanol The compound of formula X whrein R2 is trans hydroxyl is obtained by treatment of an epoxide XI with diamine of the formula XII H2N—( ——NH2 Ri o in an alcoholic solvent, such as ethanol, 24 5 3 0 0 HA488b The preparation of the epoxide XI is described by Evans and Lang (references above).

Compounds of formula X can also be prepared from the amino alcohol III and an alkylating agent of the formula wherein P is a protecting group and X is a leaving group, such as CI, Br and I, in the presence of a base catalyst, followed by deprotection. Compounds of formula X can also be prepared from a ketone or aldehyde of formula XIII (i.e., wherein X is oxo) and amino alcohol III by standard techniques of reductive amination followed by removal of the protection group P.

The compounds of the present invention wherein R2 is OCOalkyl can be prepared by acylation of the alcohol of formula I, wherein R2 is OH, with an acid chloride of the formula XIV alkyl^\cl in 'che presence of a base catalyst, such as pyridine or triethylamine.

For the preparation of individual enantiomers of compounds of formula I (wherein R2 =H, OH), compound.Ill (R2 = =H, OH) is converted to diastereomeric amides of the formula N=P XIII ? 4 5 3 0 HA488b =o XVI R5^\ ^+-R3 c . 0 R« by treatment with chiral nonracemic mandelic acid in the presence of dicyclohexylcarbodiimide.

Compounds XV and XVI are separated by crystallization or chromatography. The enantiomer 25 of mandelic acid that yields crystalline diastereomer with the desired 4R-stereochemistry of benzopyran (as shown in formula XV) is preferred in the resolution step.

Compounds XV and XVI are then hydrolyzed by 30 heating in the presence of sulfuric acid in dioxane to give enantiomers of the formula 24 5 3 0 0 HA488b XVII and XVIII *!H2 V^iR3 R 4 The enantiomers XVII and XVIII are then converted to chiral nonracemic compounds of formula I.

The compounds of the present invention can have asymmetric centers at carbons 2-4 of 20 benzopyran ring. Also, any one of the R's can have an asymmetric carbon. Consequently, compounds of formula I can exist in diastereomeric forms or in mixtures thereof. The above described process can utilize racemates, enantiomers or diastereomers as 25 starting materials. When diastereomeric products are prepared, they'can be separated by conventional chromatographic or fractional crystallization methods.

The compounds of the present invention 30 wherein R9 and/or Rg is hydrogen, can exist as a mixture of tautomers represented hv the following structures. The tautomeric products are obtained in relative amounts that differ from compound to 245300 HA488b compound. All forms are included in the scope of formula I. i • R7 Rs ~^S)=NCN r9-n /' s=€Cp: i i » R7 \ N.

R9-N nhcn 245300 HA488b The compounds of formula I and the pharmaceutically acceptable salts act as potassium channel activators. Thus," compounds of the present invention are useful as anti-arrhythmic agents, 5 antiischemic agents and in the treatment of hypertens ion.

It has been found that compounds of formula I wherein R7 is aryl, arylalkyl, cycloalkyl, (cycloalkyl)alkyl, heterocyclo or (heterocyclo)-10 alkyl are preferred as antiischemic agents, i.e., for the treatment of ischemic conditions such as myocardial ischemia, cerebral ischemia, lower limb ischemia and the like. Especially preferred are those compounds where R7 is aryl or arylalkyl and 15 R8 and Rg are each hydrogen. While any of the compounds of formula I may be used as antiischemic agents, these preferred antiischemic agents have been found to possess little or no vasodilator activity. This means that in the treatment of 20 ischemic heart, these compounds are less likely to cause coronary steal, profound hypotension and coronary underperfusion.' Similarly, the most preferred compounds of formula I for reducing hypertension are those 25 wherein R7 is hydrogen or alkyl of 1 to 3 carbons, R7 and R8 taken together with the nitrogen atom to which they are attached for a 5- or 6-membered ring, such as pyrrolidine or piperidene, R9 and Rj. o are each hydrogen and n is 1 or 2. 30 Thus, for example, by the administration of a composition containing one (or a combination) of the compounds of this invention, ischemic conditions of a mammalian (e.g., human) host are reduced. A 24 5 3 0 0 HA488b single dose, or preferably two to four divided daily doses, provided on a basis of about 0.001 to 100 mg per kilogram of body weight per day, preferably from about 0.1 to about 25 mg per kilogram per day, is appropriate to reduce ischemic conditions. The substance is preferably administered orally, but parenteral routes, such as the subcutaneous, intramuscular, or intravenous routes or any other convenient delivery system, such as inhalation or intranasal solutions or transdermal patches, can also be employed. The above doses are also suitable for the other cardiovascular (e.g., hypertension) and non-cardiovascular uses.

As a result of the potassium channel activating activity of compounds of this invention, these compounds are also useful in the treatment of cardiovascular disorders and any disorders associated with smooth muscle contraction. For example, compounds of the present invention are useful as therapy for congestive heart failure, therapy for peripheral vascular disorders (e.g.

Raynaud's Disease), therapy for pulmonary hypertension, as anti-anginal agents, as anti-fibrillatory agents, as thrombolytic agents and in limiting myocardial infarction.

Compounds of the present invention are additionally expected to be useful in the treatment of central nervous.system disorders (e.g., Parkinsonism, as anti-tremor agents, epilepsy), in therapy for renal failure, in therapy for urinary incontinence, as anti-diarrheal agents, in therapy for pre-eclampsia, dysmenorrhea and premature labor, as well as for the promotion of hair growth (e.g., in the treatment 24 5 3 0 0 HA488b of male pattern baldness) and as anti-asthmatic agents.

The compounds of this invention can also be formulated in combination with a diuretic such as, chlorothiazide, hydrochlorothiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methylchlothiazide, trichloromethiazide, polythiazide or benzthiazide as well as ethacrynic acid, tricrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triamterene, amiloride and spironolactone and salts of such compounds, angiotensin converting enzyme inhibitors such as captopril, zofenopril, fosinopril; enalapril, ceranopril, cilazopril, delapril, pentopril, quinapril, ramipril, lisinopril, and salts of such compounds, thrombolytic agents such as tissue plasminogen activator (tPA), recombinant tPA, streptokinase, urokinase, prourokinase, and anisoylated plasminogen streptokinase activator complex (APSAC, Eminase, Beecham Laboratories), or calcium channel blocking agents such as nifedipine or diltiazem. Such combination products if formulated as a fixed dose employ the compounds of this invention within the dose range described above and the other pharmaceutically active agent within its approved dose range.

The compounds of formula I, and combinations thereof, can be formulated, as described above, in compositions such as tablets, capsules or elixirs for oral administration, in sterile solutions or suspensions for parenteral administration, and may also be administered via transdermal patch or nasal inhalation solutions. About 10 to 500 milligrams 245300 HA488b of a compound of formula I is compounded with physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for 5 by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.

As mentioned above the compounds herein have also been found useful in preventing/alleviating tissue and cell damage in organ surgery procedures, e.g., bypass and transplant.

Cardiopulmonary bypass and heart transplant are two important surgical procedures used by cardiac surgeons. While they both are designed to improve cardiac functional status, the techniques could be greatly improved. In both cases, the procedures require that the hearts be removed ffrom the normal circulation of the body and thus by 20 definition, some degree of damage may be observed. In bypass and transplant, cardioplegic solution, rather than blood, are employed to perfuse the coronary arteries. Accordingly, the conditions and attendant risks/damage resulting from these 25 procedures may differ from coronary stenosis induced damage. To reduce the degree of surgical damage, the hearts are perfused in a retrograde fashion with a cardioplegic solution designed to reduce energy need's of the tissue by arresting the hearts, making them hypothermic (reduce energy demands) and also supplying them with essential substrates.

In carrying out cardiopulmonary bypass and heart transplant according to the present invention, a potassium channel activator is added to any solution used to perfuse the coronary arteries or used in connection with bypass and transplant procedures. These solutions may be selected from any of the various cardioplegic solutions, intracellular solutions, etc., which are used to perfuse the arteries, to store the organ, to arrest the heart for transplant, etc.

Additionally, the present invention encompasses administration of a potassium channel activator to a mammalian specie, i.e., monkey, dog, cat, rat, human, etc., which is involved in the bypass or transplant procedure. For example, a potassium channel activator can be administered to a bypass patient, organ donor and/or organ recipient before, during and/or after the bypass or transplant procedure.

While the present invention relating to transplant procedures is most frequently described in terms of heart transplant, other types of organ transplant are also described herein.

Organ transplant procedures which would also benefit fsom use of a potassium channel activator, especially the ischemia selective activators, include liver and kidney transplants.

When administered to the mammalian organ donor or recipient or bypass patient, the. dosage of potassium-channel activator should be in the range of 1-50 mg/kg. Administration to donor/recipient can be by any techniques known in the medical arts, e.g., orally, parenterally, intranasally, 245300 transdermally and the like, using known pharmaceutically acceptable formulations and delivery systems. This can be accomplished by compounding about 10 to 500 milligrams of a potassium channel activator into a pharmaceutically acceptable carrier by known techniques.

The potassium-channel activator can be present in the cardioplegic solutions in concentrations from about 3 |iM to 60 |1M and preferably is present in an amount ranging from 7 |1M to 30 |iM.

Preferred are those compounds wherein Ri is chloro or fluoro; ^ r2 is trans-hydroxy; R3 and R4 are each methyl,-R5 is -CN or -NO2; R6 is hydrogen; R7 is hydrogen; R8 is hydrogen; and, Rg is hydrogen.

The most preferred compounds of the present inventions are where Ri is chloro or fluoro.

Specific embodiments of the present invention are described hereinafter in the following examples.

Preferred compouri&s are those wherein a is nitrogen or -CR5; b and c are each -CH-; Rx is Vs / Ra =NCN or Rio" Rg-N ( -N, n <=NCN; I R2 is hydroxy; R3 and R4 are each alkyl; .Rs is an electron withdrawing group; R6 is hydrogen, alkyl, O-alkyl, amino; R7 is hydrogen, alkyl, aryl or arylalkyl Rs is hydrogen; R9 is hydrogen or alkyl; R10 is hydrogen; and, n is 1 or 2. 1 ^ 245300 HA488b 23 Most preferred are those compounds wherein a is nitrogen or -CRS; b and o are each -CH-; R2 is trans-hydroxy; R3 and R4 are each methyl; R5 is -CN or -N02; Rs is hydrogen; R? is methyl, ethyl, phenyl or phenylmethyl; Rg is hydrogen; R9 is hydrogen; R10 is hydrogen; and n is 1.

The preferred compound of the present invention, which is preferably employed as an 15 antiischemic agent, is Specific embodiments of the present invention are described hereinafter in the following examples. 24 5 3 0 HA488b 24 Example 1 (trans) -N"-Cyano-N- (6-cyan'o-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyr an-4-yl) -N' - (1,1-dimethyl-5 propyl)quanidine A. N-Cyano-N'-(1,1-dimethylpropyl)thiourea To a suspension of monosodiurc cyanamide (0.64 g, 10 ramol) in absolute ethanol (30 mL), 10 1,1-dimethylpropylisothiocyanate (1.29 g, 10 mmol) was added slowly at room temperature. Exothermic reaction occurred during addition and near the end of the addition, the initially heterogeneous mixture became a homogeneous solution. It was 15 allowed to stir at room temperature for 2 hours and then heated at 75°C for 1 hour. The reaction mixture was cooled to room temperature and the solid was filtered. The filtrate solution was concentrated to yield the title A compound (1.6 g) 20 as a colorless solid.

B. (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N' - (1,1-dimethylpropyl)quanidine To a solution of the title A compound (0.94 g, 5.5 mmol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and'J. Med. Chem., 1986, 29, 2194) 30 (1.0 g, 4.6 mmol) in dimethylformamide (5 mL) under argon, 1- (3-dimethylaminopropyl )-2-ethylcarbodiimide hydrochloride (1.14 g, 5.9 mmol) was added at room temperature. The reaction mixture was stirred at 24 5 3 0 0 HA488b room temperature for 2 hours and then partitioned between IN HC1 and ethyl acetate. The organic layer was separated and the aqueous phase was reextracted with ethyl acetate and the combined 5 organic phase was washed with water, aqueous sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the filtrate was concentrated and the residue was purified by flash chromatography on silica gel (1:1 Hexane/EtOAc). The fractions 10 containing the desired product were combined and concentrated to yield a colorless solid (620 mg).

This solid was triturated with isopropyl ether to yield the title compound, m.p. 207-208°C.

Analysis calc'd for Cjgl^sNsC^: C, 64.20; H, 7.09; N, 19.71; Found: C, 64.04; H, 7.11; N, 19.44.

Example 2 2 0 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy- 2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-ethyl quanidine A. N-Cyano-N1-ethylthiourea To a suspension of monosodium cyanamide (6.4 25 g, 100 mmol) in absolute ethanol (30 mL), ethyl- isothiocyanate (9.0 mL, 100 mmol) was added slowly with stirring at room temperature. During addition, exothermic reaction occurred and near the end of the addition the reaction mixture became a homogeneous 30 solution. It was allowed to stir at room temperature for 2 hours and then heated at 75°C for 1 hour. The reaction mixture was cooled to room 24 5 3 HA488b 26 temperature and the insoluble material was filtered off (700 mg). The mother liquor was concentrated and the resulting solid was triturated with isopropanol-isopropyl ether to yield the title A 5 compound (11.2 g), m.p. >240°C.

B. (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3- hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N1-ethyl quanidine To a solution of the title A compound (1.15 g, 8.9 mmol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (prepared according to Evans et a'l., J Med. Chem., 1983, 26, 1582 and J. Med. Chem., 1986, 29, 2194). 15 (1.5 g, 6.9 mmol) in dimethylformamide (5 mL) under argon was added l-(3-dimethylaminopropyl)-2-ethyl-carbodiimide hydrochloride (1.71 g, 8.9 mmol) at room temperature. The reaction mixture was stirred at room temperature for 2 hours and then partitioned 20 between IN HC1 and ethyl acetate. The organic phase was separated and the aqueous phase was reextracted with ethyl acetate. The combined organic phase was washed with water, aqueous sodium bicarbonate and brine. After drying over anhydrous 25 magnesium sulfate, the solvent was evaporated and the residue was purified by flash chromatography on silica gel (25% acetone in dichloromethane). The fractions containing the desirad product were combined and evaporated to yield a colorless solid 30 (801 mg). This solid product was recrystallized from acetonitrile-ether to yield the title compound, m.p. 185-188°C. 245300 HA488b 27 Analysis calc'd for C16H19N502 0.2 H20: C, 60.64; H, 6.17; N, 22.10; Found: C, 60,63; H, 6.16; N, 22.25.

Example 3 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-phenyl quanidine A. N-cyano-N'-phenylthiourea To a suspension of monosodium cyanamide (6.4 g, 100 mmol) in absolute ethanol (170 mL), phenyl-isothiocyanate (12.5 mL, 104.5 mmol) was added 15 slowly with stirring at room temperature. The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid was filtered and washed with 20 ethanol to give the title A compound (13.6 g), m.p. >250°C.

B. (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N'-phenyl quanidine To a solution of the title A compound (1.06 g, 5.96 mmol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbonitri1e (prepared according to Evans et al., J. Med. Chem., 30 1983, 26, 1582 and J. Med. Chem., 1986, 29, 2194). (1.0 g, 4.59 mmol) in dimethylformamide (5 mL) under argon, l-(3-dimethylaminopropyl)-2-ethyl-carbodiimide hydrochloride'(1.17 g, 5.96 mmol) was 24 5 3 0 0 HA488b 28 added at room temperature. The reaction mixture was stirred at room temperature for 2 hours and then partitioned between IN HC1 and ethyl acetate. The organic phase was separated and the aqueous phase was reextracted with ethyl acetate and the combined organic phase was washed with water, aqueous sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the colorless residue w^s triturated with ether to yield the title compound (1.3 g), m.p. 247-249°C (with effervescence).

Analysis calc'd for C2oHi9Ns02: C, 66.46; H, 5.30; N, 19.3*8; Found: C, 66.09; H, 5.30; N, 19.35.

Example 4 (trans)-N"-Cyano-N-(3,4-dihydro > --3-hydroxy-2,2-dimethyl-6-nitro-2H-l-benzopyran-4-yl )-N' - ethyl-quanidine To a solution of the title A compound from Example 2 (1.2 g, 9.4 mmol) and (trans)-4-amino-3,4-dihydro-2,2-dimethyl-6-nitro-2H-l-benzopyran (1.5 g, 6.3 mmol) (prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med. Chem., 1986, 29, 2194) in dimethylformamide (5 ml) under argon, 1- (3-dimethyl aminopropyl) -2-ethylcarbodi- * imide hydrochloride (2.1 g, 10.7 mmol) was added at room temperature. The reaction mixture was stirred at room temperature for 2 hours and then partitioned between IN HC1 and ethyl acetate. The organic phase was taken and the aqueous phase was reextracted with ethyl acetate and the combined organic phase was washed with water, aqueous sodium bicarbonate 245300 HA488b 29 and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was purified by flash chromatography on silica gel (Hexane/Acetone/6:4) to yield a colorless solid 5 (500 mg).

This was triturated with isopropyl ether to provide the title compound, m.p. 204-205°C.

Analysis calc'd for CxsHi9N504•0.17 H20: C, 53.55; H, 5.79; N, 20.82; Found: C, 53.89; H, 5.63; N, 20.48.

Example 5 (trans)-3,4-Dihydro-3-hydroxy-2,2-dimethyl-4-[2-15 (cyanoimino)-1-pyrrolidinyl]-2H-l-benzopyran-6-carbonitrile A. (trans)-4-[(2-Aminoethyl)amino]-3,4-dihydro- 3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6- carbonitrile To a suspension of 6-cyano-3,4-epoxy-3,4-dihydro-2,2-dimethyl-2H-benzopyran (1.2 g, 5.97 mmol) (prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med. Chem., 25 1986, 29, 2194) in ethanol (7.0 mL), ethylene-diamine (2.4 mL, 35.8 mmol) was added at room temperature and the reaction mixture was stirred at room temperature for 36 hours. The solvent was removed under reduced pressure and the residue was 30 further dried by use of vacuum pump to yield the title A compound (1.74 g, >100%) as a colorless foam. This material was used for the next reaction without any purification. 245300 HA488b B. (trans)-3,4-Dihydro-3-hydroxy-2,2-dimethyl- 4-[2-(cyanoimino)-1-pyrrolidinyl]-2H-1- benzopyran-6-carbonitrile To a solution of the title A compound (1.74 5 g, 5.97 mmol) in ethanol at room temperature, triethylamine (1.7 mL, 11.94 mmol) was added slowly, followed by dimethyl N-cyanodithioimino-carbonate (1.16 g, 11.94 mmol of 90%). The reaction mixture was heated at 80°C for 3 hours and 10 then cooled to ambient temperature. The solvent was evaporated to give a light yellow foam (2.4 g). This material was taken up in methanol (20 mL) and the resulting suspension was treated with mercuric acetate (2.52 g, 7.77 mmol). The reaction mixture 15 was stirred at room temperature for 2 hours and the solvent was evaporated under reduced pressure. The residue was diluted with water, alkalized to pH ~ 9.0 with 5N NaOH and the product was extracted with 5% methanolic chloroform. The combined organic 20 extracts were washed with brine whereby a thick emulsion resulted. The two phase mixture was filtered through a celite pad and the organic layer was separated and dried over magnesium sulfate. The solvent was evaporated and the residue was 25 purified by flash chromatography (5% methanol in chloroform) on silica gel to provide a colorless residue. This residue was triturated with ethyl acetate to yield the desired product (740 mg). The mother liquour was-concentrated and triturated with 30 ethyl acetate to provide a second crop (370 mg) for a total of 1.1 g. The combined material was recrystallized from hot ethyl accetate to give the title compound as a white powder, m.p. 254-255°C. 24 5 3 0 0 HA488b 31 Analysis calc'd for C16H17N502 0.42 H20: C, 60.27; H, 5.63; N, 21.97; Found: C, 60.40; H, 5.30; N, 21.84.

Example 6 (trans)-N"-Cyano-N-(3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-pyrano[3,2-c]pyridin-4-yl)-phenylguanidine To a solution of the title A compound from Example 3 (2.2 g, 12.5 mmol) and (trans)-4-amino-3,4-dihydro-2,2-dimethyl-2H-pyrario[3,2-c]pyridin-3- *. ol (1.1 g, 5.7 mmol) (prepared according to EP 0 205 292 A2) in dimethyl formamide (5 ml) under argon, l-(3-dimethylaminopropyl)-2-ethylcarbodi-imide hydrochloride (2.2 g, 10.8 mmol) was added at room temperature. The reaction mixture was stirred at room temperature for 2 hours and then partitioned between water (pH ~ 11) and ethyl acetate. The organic phase was separated and tba aqueous phase was reextracted with ethyl acetate and the combined organic phase was washed with water, aqueous sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was purified by flash chromatography on silica gel (acetone:dichloromethane/l:4) to yield a colorless solid (470 mg) which was crystallized * from acetonitrile -to provide the title compound, m.p. 233-236°C.

Analysis calc'd for C18H19Ns02: C, 64.08; H, 5.67; N, 20.76; Found: C, 63.88; H, 5.48; N, 20.76. 245300 HA488b 32 Example 7 (trans)-N1-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-l-pyrrolidine-5 carboximidamide A. (trans)-4-[[(Cyanoimino)phenoxymethy1]amino]-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile To a solution of (trans)-4-amino-3,4-dihydro- 3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med. Chem.,' 1986, 29, 2194) (5.0 g, 23 mmol) in isopropanol (50 mL), diphenyl-15 cyanocarbonimidate (5.5 g, 25 mmol) was added at room temperature and the reaction mixture was allowed to stir at room temperature for 16 hours.

Most of the isopropanol was evaporated and the residue was dissolved in ethyl acetate. The 20 resulting solution was washed successively with % citric acid, IN sodium hydroxide solution and brine. It was dried over anhydrous magnesium sulfate, concentrated and the residue was crystallized from chloroform-isopropyl ether to 25 yield the title A compound (4.2 g) as a colorless solid, m.p. 186-188°C.

Analysis calc'd for C2oHi8N403♦0.6H20: C, 64.37; H, 5.18; N, 15.02; Found: C, 64.64; H> 4.86; N, 14.75.

B. (trans)-N'-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- 1-pyrrolidine-carboximidamide To a solution of title A compound (0.8 g, 12.2 mmol) in isopropanol (4 mL), pyrrolidine (0.5 24 5 3 0 HA488b 33 mL) was added at room temperature arid the reaction mixture was allowed to stir at room temperature overnight. The suspension was diluted with ether and the colorless solid was filtered and dried to 5 yield the title compound (0.4 g), m.p. 263-264°C. Analysis calc'd for C18H2iNs02: C, 63.70; H, 6.24; N, 20.64; Found: C, 63.45; H, 6.29; N, 20.88.

Example 8 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-ethyl-N-methylguanidine A. (trans)-N1-Cyano-N-(6-cyano-3,4-dihydro-3- hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N-methylcarbamidic acid, phenyl ester To a solution of (trans)-3,4-dihydro-3-hydroxy-20 2,2-dimethyl-4-(methylamino)-2H-l-benzopyran-6-carbonitrile (prepared according to Evans et al., J♦ Med. Chem., 1983, 26,. 1582 and J. Med. Chem., 1986, 29, 2194) (1.0 g, 4.3 mmol) in isopropanol (4 mL), diphenylcyanocarbonimidate (1.0 g, 4.3 25 mmol) was added at room temperature and the reaction mixture was allowed to stir at room temperature for 16 hours. Most of the isopropanol was evaporated and the residue was dissolved in ethyl acetate. The resulting solution was washed successively with 30 10% citric acid, IN sodium hydroxide and brine. It was dried over anhydrous magnesium sulfate and concentrated. The resiude was purified by flash 245300 HA488b 34 chromatography (ethyl acetate:hexanes 1:1) on silica gel to yield the title A compound. This compound was used for the next step without further purification.

B. (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3- hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N'-ethyl-N-methylquanidine To a solution of the title A compound (0.1 g, 0.27 mmol) in isopropanol (1 mL) and triethyl amine (0.25 mL), ethyl amine hydrochloride (0.1 g, 1.2 mmol) was added at room temperature and the reaction mixture was allowed to stir at room temperature overnight. Most of the solvent was evaporated and the residue was dissolved in ethyl acetate. The solution was washed successively with 10% citric acid, aqueous sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was triturated with ether to yield the title compound as a colorless solid, m.p. 227-228°C.

Example 9 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-[2(dimethyl- amino)ethyl1quanidine * To a suspension of the compound from Example 7, part A (0.8 g, 2.2 mmol) in isopropanol (3 ml), 95% 1,1-dimethylethylenediamine (0.5 g, 5.7 mmol) was added at room temperature. It was allowed to stir at room temperature for 20 hours and 245300 HA488b concentrated in vacuo. The residue was triturated with isopropyl ether to give the title compound (0.4 g) as a white solid, m.p. 172-173°C: XH NMR (CDC13) 67.6 (s, 1 H), 7.4 (dd, J = 2.0 & 9.0 Hz, 5 1H), 6.9 (d, J = 9.0 Hz, 1 H), 6.6 (s, 1 H), 4.9 (t, J = 9.0 Hz, 2 H), 3.5 (d, J = 9.0 Hz, 1 H), 3.4 (s, 2 H), 2.5 (m, 2 H), 2.0 (s, 6 H), 1.5 (s, 3 H), 1.3 (s, 3 H); 13C NMR (CDC13) 6 163.4, 156.8, 133.1, 132.5, 122.8, 118.8, 118.7, 118.0, 103.9, 10 80.4, 76.2, 69.1, 60.8, 51.8, 44.6, 41.7, 26.4, 18.5; IR (KBr) 1126.9, 1267.0, 1431.4, 1489.0, 1577.0, 1635.8, 2173.3, 3391.9, 3407.6 cm"1. Analysis calc'd for C18H2 4N602: C, 60.65; H, 6.79; N, 23.58; Found: C, 60.53; H, 6.75; N, 23.62.

Example 10 (trans) -N" -Cyano-N- (6-cyano-3,4-dihydro-3 -20 hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl) -N' -methylquanidine To a suspension of the compound of Example 7, part A (1.0 g, 2.8 mmol) in isopropanol (6 ml), 25 methylamine (40% solution in methanol, 1 ml) was added at room temperature. The reaction mixture was allowed to stir at room temperature for 20 hours and concentrated in vacuo. The crude product obtained was crystallized from isopropanol to give 30 the title compound (0.4 g) as a white solid, m.p. 212-214°C: XH NMR (CDCl3/DMSO) 6 7.5 (s, 1 H), 7.45 (d, J = 9.0 Hz, 1 H), 6.9 (m, 2 H), 6.3 (d, J = 8.0 Hz, 1 H), 5.55 (br, 1 H), 4.85 (br, 1 H), 3.7 (m, 1 2 4 5 3 0 0 HA488b 36 H), 2.83 (d, J = 5.0 Hz, 3 H), 1.48 (s, 3 H), 1.24 (s, 3 H); 13C NMR (CDC13/DMS0) 160.5, 155.5, 131.6, 131.3, 123.7, 117.9, 117.3, 116.9, 102.2, 79.4, 76.6, 70.9, 27.6, 25.6, 17.7; IR (KBr) 1267, 1419, 5 1489, 1576, 1608, 2170, 2225, 2977, 3338 cm"1. Analysis calc'd for C^H^NsC^-0.3 H20: C, 59.16; H, 5.82; N, 23.01; Found: C, 59.16; H, 5.57; N, 23.01.

Example 11 (trans)-4-[(Cyanoimino)[[4-(phenylmethyl)-l-piper-az inyl]methyl]amino]-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile To a suspension of the compound from Example 7, part A (2.0 g, 5.5 mmol) in isopropanol (5 ml), 4-(phenylmethyl)-l-piperazine (1.0 ml) was added at room temperature. The reaction mixture 20 was allowed to stir at room temperature for 20 hours and concentrated in vacuo. The crude product obtained was purified by- flash chromatography on silica gel eluting with dichloromethane/acetone (7/3) to give the title compound (0.6 g). It was 25 recrystallized from isopropanol-ether to give the desired product (250 mg) as a white solid, m.p. 205-207°C: *H NMR (DMSO-d6) 6 7.4 (s, 1 H), 7.3 (d, J = 8.0 Hz, 1 H), 7.2 (d, J = 8.0 Hz, 1 H), 7.0 (s, 6 H), 6.6 (d, J ='-9.0 Hz, 1 H), 5.6 (d, J = 6.0 Hz, 30 1 H), 4.6 (t, J = 8.0 & 10.0 Hz, 1 H), 3.2 (m, 5 H), 2.2 (m, 5 H), 1.14 (s, 3 H), 0.88 (s, 3 H); l3C NMR (DMS0-d6) 161.1, 156.4, 137.6, 133.1, 132.9, 24 5 3 0 0 HA488b 37 129,1, 128.3, 127.2, 124.6, 117.9, 102.7, 80.6, 71.5, 61.9, 53.0, 52.2, 46.6, 26.7, 18.6; IR (KBr) 1125, 1490, 1524, 1577, 1611, 2170, 2224, 3429 -1 cm Analysis calc'd for C2SH28N602: C, 67.54; H, 6.35; N, 18.91; Found: C, 67.29; H, 6.37; N, 18.73.

Example 12 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)quanidine To a suspension of the compound of Example 15 7, part A (1.0 g, 2.8 mmol) in isopropanol (6 ml), ammonium hydroxide (1" ml) was added at room temperature. It was allowed to stir at room temperature for 20 hours and concentrated in vacuo. The crude product obtained was crystallized 20 from acetone/ethyl acetate to give the title compound (0.31 g) as a white solid, m.p. 250-251°C: NMR (DMSO-dg) 6 7.7 (dd, J = 2.0 & 7.0 Hz, 1 H), 7.5 (s, 1 H), 6.9 (m, 2 H), 7.0 (d, J = 9.0 Hz, 1 H), 5.8 (br s, 1 H), 4.8 (br s, 1 H), 3.6 (m, 1 H), 25 1.48 (s, 3 H), 1.25 (s, 3 H); 13C NMR (DMSO-d6) 162.3, 156.3, 132.9, 132.6, 124.8, 119.1, 118.1, 102.7, 80.5, 71.3, 26.5, 19.0; IR (KBr) 1064, 1268, 1489.7, 1555, 1635, 2183, 2225, 3432 cm"1.

Analysis calc'd for C14H15N502: 30 C, 58.93; H, 5.30; N, 24.55; Found: C, 58.74; H, 5.32; N, 24.23. 245300 t; HA488b 38 j Example 13 , » i ■ • < (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N1 -(methyl-5 ethyl)quanidine To a suspension of the compound from Example 7, part A (2.0 g, 5.5 mmol) in isopropanol (5 ml), isopropylamine (1.5 ml) was added at room 10 temperature. It was allowed to stir at room temperature for 20 hours and concentrated in vacuo. The crude product obtained was purified by flash chromatography on silica gel eluting with 7/3 dichloromethane/acetone to give the title compound 15 (1.2 g). This solid was crystallized from isopropanol-isopropyl ether to give the desired product as a white solid, m.p. 150-152°C; XH NMR (DMSO-ds) 6 7.6 (dd, J = 2.0 & 7.0 Hz, 1 H), 7.5 (s, 1 H), 7.2 (d, J = 9.0 Hz, 1 H), 7.0 (d, J = 20 9.0 Hz, 1 H), 6.8 (d, J = 8.0 Hz, 1 H), 5.9 (d, J = 5.0 Hz, 1 H), 4.8 (t, J = 9.0 Hz, 1 H), 3.9 (m, 1 H), 3.8 (m, 1 H), 1.47 (s, 3 H), 1.24 (s, 3 H), 1.2 (d, J = 3.0 Hz, 6 H); 13C NMR (DMS0-d6) 159.5, 156.3, 132.7, 132.4, 125.2, 119.1, 118.0, 117.8, 25 102.7, 80.5, 71.1, 51.5, 43.4, 26.7, 22.6, 22.4, 18.7; IR (KBr) 1268, 1490, 1587.8, 2170, 2226, 2978, 3419 cm"1.

Analysis calc'd for Cx7H2:N502•0.1 H20: C, 62.03; Ht 6.49; N, 21.28; Found: C, 61.75; H, 6.66; N, 21.86. 24 5 3 0 0 HA488b 39 Example 14 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-dimethyl-guanidine To a suspension of the compound from Example 7, part A (1.0 g, 2.8 mmol) in isopropanol (6 ml), dimethylamine hydrochloride (0.33 g, 4.2 mmol) was added, followed by powdered potassium carbonate (0.57 g, 4.2 mmol) at room temperature. The reaction mixture was allowed to stir at room temperature for 20 hours and concentrated in vacuo. The residue was dissolved in chloroform (150 ml) and washed with water, dried over magnesium sulfate and concentrated in vacuo. The crude product obtained was crystallized from dichloromethane-ether to give the title compound (0.44 g) as a white solid.

This solid was recrystallized from acetonitrile-chloroform to give colorless solid, m.p. 196-197°C. lH NMR (DMSO-ds) 6 7.7 (s, 1 H), 7.6 (dd, J = 3.0 & 8.0 Hz, 1 H), 7.2 (d, J = 9.0 Hz, 1 H), 6.9 (d, J = 9.0 Hz, 1 H), 5.8 (d, J = 6.0 Hz, 1 H), 4.9 (t, J = 9.0 & 10.0 Hz, 1 H), 3.6 (dd, J = 8.0 & 5.0 Hz, 1 H), 3.0 (s, 6 H), 1.42 (s, 3 H), 1.24 (s, 3 H); 13C NMR (DMS0-d6) 159.3, 154.9, 131.5, 130.8, 123.4, 116.1, 101.4, 78.9, 70.3, 51.5, 25.2, 17.0; IR (KBr) 1143, 1269, 1398, 1489, 1527, 1595, 2168, 2226, 2935, 2980, *3433 cm"1.

Analysis calc'd for C16H19Ns02•0.5 HzO: C, 59.61; H, 6.25; N, 21.73; Found: C, 59.44; H, 5.95; N, 22.03. 245300 HA488b 40 Example 15 (trans) -N"-Cyano-N- (6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-phenylmethyl-5 quanidine T6 a suspension of the compound from Example 7, part A (0.5 g, 1.4 mmol) in isopropanol (3 ml) was added benzylamine (90% 0.5 ml) at room 10 temperature. The reaction mixture was allowed to stir at room temperature for 20 hours and concentrated in vacuo. The residue was combined with another batch of the same material and purified by flash chromatography on silica gel eluting with hexane-15 ethyl acetate (3:7) to give a white solid (0.8 g).

This solid was crystallized from acetonitrile-isopropyl ether to give the title compound as a colorless solid, m.p. 188-189°C: XH NMR (CDC13) 6 7.7 (m, 1 H), 7.5 (dd, J = 2.0 & 9.0 Hz, 1 H), 7.4 20 (m, 6 H), 6.86 (d, J = 9.0 Hz, 1 H), 5.8 (s, 1 H), 4.8 (m, 1 H), 4.5 (d, J = 5.0 Hz, 2 H), 3.7 (dd, J = 6.0 & 4.0 Hz, 1 H), 1.41 (s, 3 H), 1.19 (s, 3 H); 13C NMR (CDC13) 158.7, 154.5, 136.8, 130.7, 126.5, 125.2, 125.0, 123.0, 116.0, 101.0, 78.6, 42.6, 24.8, 16.9; IR (KBr) 1267, 1491, 1579, 1595, 2175, 2222, 3433 cm"1.

Analysis calc'd for C2iH2iN502: C, 67.18; H, 5.64; N, 18.66; Found: C, 67.14; H> 5.55; N, 18.65. 245300 HA488b 41 Example 16 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N1-[2-[(phenyl-5 methyl)methylamino]ethyl]quanidine To a suspension of the compound from Example 7, part A (0.5 g, 1.4 mmol) in isopropanol (3 ml), N-methylbenzylethylamine (0.5 ml) was added 10 at room temperature. The reaction mixture was allowed to stir at room temperature for 24 hours. The initially heterogeneous mixture became a homogeneous solution slowly and as the reaction proceeded the product precipitated out of the 15 reaction mixture. Upon completion of reaction, the solid was filtered and triturated with ether to give the title compound (0.45 g) as a colorless solid, m.p. 184-185°C: 1H NMR (CDC13) 6 9.4 (s, 1 H), 7.59 (d, J = 8.0 HZ, 1 H), 7.2 (m, 4 H), 6.96 20 (s, 2 H), 6.87 (d, J = 9.0 Hz, 1 H), 6.4 (s, 1 H), 4.9 (m, 2 H), 3.4 (m, 4 H), 2.6 (m, 2 H), 2.1 (s, 3 H), 1.49 (S, 3 H), 1.26 (s, 3 H); 13C NMR (CDC13) 205.2, 160.7, 155.6, 131.6, 128.0, 127.4, 126.2, 123.5, 118.0, 117.3, 117.1, 102.4, 79.4, 61.3, 25 55.6, 40.5, 25.7, 17.74; IR (KBr) 1126, 1267, 1489, 1575, 1608, 2172, 2224, 2800, 2976, 3421 cm"1. Analysis calc'd for C24H28N6o2: C, 66.64; H, 6.52; N, 19.43; Found: C, 6'o.40; H', 6.52; N, 19.99. 2 4 5 3 HA488b 42 Example 17 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4yl)-N1-(2-methoxy-5 ethyl)quanidine To a suspension of the compound from Example 7, part A (0.5 g, 1.4 mmol) in isopropanol (3 ml), 2-methoxyethylamine (0.12 g, 1.7 mmol, 0.15 ml) was 10 added at room temperature. The reaction mixture was allowed to stir at room temperature for 20 hours and concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with ethyl acetate to give the title 15 compound (0.3 g) as a colorless solid, m.p. 94-96°C: *H NMR (CDC1'3) 6 7.5 (s, 1 H), 7.38 (d, J = 7.0 Hz, 1 H), 6.8 (m, 3 H), 4.86 (s, 1 H), 4.0 (m, 1 H), 3.5 (m, 4 H), 3.2 (s, 3 H), 1.9 (s, 1 H), 1.43 (s, 3 H), 1.19 (s, 3 H); 13C NMR (CDC13) 20 162.6, 156.8, 133.2, 132.4, 122.5, 119.0, 118.5, 118.1, 103.9, 80.2, 74.7, 60.3, 58.9, 52.2, 26.4, 21.0, 18.7, 14.1; IR (KBr) 1635, 1693, 3404 cm"1. Analysis calc'd for C17H2iN503•0.24 H20: C, 58.71; H, 6.23; N, 20.14; Found: C, 58.81; H, 6.38; N, 20.04. 245300 HA488b 43 Example 18 (3S-trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-phenylquanidine A. [3R-[3a,4p(S*)]]-N-(6-Cyano-3;4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl) ■ g-hydroxybenzeneacetamide and [3S- [3a,4p(R*)]]-N-(6-Cyan<5-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- g-hydroxybenzeneacetamide To a solution of (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzo-pyran-6-carbonitrile (prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and 20 J. Med. Chem., 1986, 29, 2194) (10.0 g, 45.9 mmol), S-(+)-mandelic acid (6.98 g, 45.9 mmol), hydroxybenzotriazole hydrate (6.2 g, 45.9 mmol) in dimethylformamide (60 ml) at 0°C was added dicyclohexylcarbodiimide (9.5 g, 45.9 mmol). It 25 was allowed to stir at room temperature for 20 hours and then cooled in an ice bath. The precipitated solid was filtered and the filtrate was concentrated in vacuo. The residue was dissolved in 5 percent methanol in chloroform and 30 washed with 1 N sodium hydroxide, 1 N hydrochloric acid, brine and dried over anhydrous magnesium sulfate. After removing drying agent, the solvent was removed in vacuo. The residue was crystallized from ethanol to give [3R-[3a,4p(S*)]]-N-(6-cyano-35 3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran- 44 2 4 5 3 0 0 HA488b 4-yl )-of-hydroxybenzeneacetamide (6.0 g) as a white solid, m.p. 238-240°C, l>D]25 = +94.6° (c = 1, MeOH): lH NMR (CDC13) 6 7.4 (m, 5 H), 7.26 (t, J = 1.0 HZ, 1 H), 6.97 (d, J = 9.0 HZ, 1 H), 6.83 (d, J 5 = 9.0 HZ, 1 H), 5.16 (s, 1 H), 4.98 (t, J = 9.0 HZ, 1 H, 3.8 (d, J = 5.0 HZ, 1 H), 3.55 (dd, J = 4.0 & 5.0 HZ, 1 H), 1.45 (S, 3 H), 1.2 (s, 3 H).

Analysis calc'd for C2oH2oN204: C, 68.17; H, 5.72; N, 7.95; Found: C, 67.92; H, 5.49; N, 8.05.

■\ The residual material of the mother liquor was purified by flash chromatography on silica gel eluting with hexane-ethyl acetate mixture (3:7) and 15 the residue was crystallized from dichloromethane-isopropyl ether to give [3S-[3a,4p(R*>]]-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-a-hydroxybenzeneacetamide (6.0 g) as a white solid, m.p. 100-102°C (foaming); [aD]2S 20 = -26.1° (c = 1, MeOH): *H NMR (DMSO-ds) 6 8.45 (d, J = 8.0 Hz, 1 H), 7.5 (m, 4 H), 7.3 (m, 2 H), 7.0 (s, 1 H), 6.88 (d, J = 8,0 Hz, 1 H), 6.2 (s, 1 H), 5.57 (d, J = 5.0 Hz, 1 H), 5.0 (s, 1 H), 4.76 (t, J = 9.0 Hz, 1 H), 3.75 (dd, J = 5.0 & 5.0 Hz, 1 H), 25 1.40 (S, 3 H), 1.15 (s, 3 H).

Analysis calc'd for C20H20N2O4-0.25 H20: C, 67.30; H, 5.78; N, 7.84; Found: C, 67.54; H, 5.95; N, 7.44.

B. (3 S-trans )-4-Amino-3,4-dihydro-3 -hydroxy- 2,2-dimethyl-2H-l-benzopyran-6-carbonitrile To a solution of [3S-[3a,40(R*)]]-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-a-hydroxybenzeneacetamide, title A 35 compound (2.8 g, 7.9 mmol) in dioxane (30 ml) was 245300 HA488b 45 added a solution of sulfuric acid (2.5 g) in water (12 ml) at room temperature and the reaction mixture was heated at reflux temperature for 24 hours. It was concentrated in vacuo and the residue was dissolved in ethyl acetate (200 ml). The organic layer was washed with 1 N sodium hydroxide (50 ml) followed by water (50 ml) and dried over anhydrous magnesium sulfate and concentrated in vacuo to give the title B compound (1.6 g) as an oils XH NMR (CDC13) 6 7.74 (s, 1 H), 7.42 (dd, J = 2.0 & 6.0 HZ, 1 H), 6.82 (d, J = 8.0 Hz, 1 H), 3.65 (d, J = 10.0 Hz, 1 H), 3.36 (d, J = 10.0 Hz, 1 H), 1.53 (s, 3 H), 1.23 (s,-3 H).

C. (3S-trans)-N"-cyano-N-(6-cyano-3,4-dihydro-3- hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N'-phenylguanidine To a solution of N-cyano-N1-phenylthiourea (1.7 g, 9.5 mmol) and the title B compound (1.6 g, 7.3 mmol) in dimethylformamide (7 mL), under argon was added l-(3-dimethylaminopropyl)-2-ethylcarbodi-imide hydrochloride (1.8 g, 9.5 mmol) at room temperature. The reaction mixture was stirred at room temperature for 2 hours and then partitioned between IN hydrochloric acid and ethyl acetate. The organic phase was separated and the aqueous phase was re -tracted with ethyl acetate. The combined extracts were washed with water, aqueous sodium bicarbonate'.and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the crude product was purified by flash chromatography on silica gel eluting with ethyl acetate/hexanes (7:3) to give a cololess solid (0.7 g). The solid was triturated with ether to yield the title compound (0.35 g) , m.p. 2 4 5 3 0 0 HA488b 46 214-216°C; |>D]2S = -34.8° (c = 0.4l7, MeOH): *H NMR (DMSO-d6) d 9.28 (S, 1 H), 7.58 (d, J = 8.0 Hz, 3 H), 7.35 (m, 4 H), 7.15 (m, 1 H), 6.90 (d, J = 8.2 Hz, 1 H), 5.92 (br s, 1 H), 4.92 (t, J = 9.0 5 Hz, 1 H), 3.72 (br d, J = 5.9 Hz, 1 H), 1.41, 1.18 (s, 3 H each); 13C NMR (DMSO-ds) 159.2, 156.3, 137.5, 132.6, 132.5, 129.0, 124.8, 124.7, 123.6, 119.0, 117.8, 117.0, 102.6, 80.4, 70.9, 51.9, 26.6, 18.6; IR(KBr) 2226, 2179, 1609, 1582, 1491, 1267 10 cm"1.

Analysis calc'd for C2oHi9N502•0.37 H20: C, 65.26; H, 5.40; N, 19.02; Found: C, 65.62; H, 5.36; N, 18.57.

Example 19 (3R-trans-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N1 -phenylqruanidine A. (3R-trans)-4-amino-3,4-dihydro-3-hydroxy- 2,2-dimethyl-2H-l-benzopyran-6-carbonitrile To a solution of [3R-[3a,40(S*)]]-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-25 4-yl)-a-hydroxybenzeneacetamide, compound of Example 18, part A (2.8 g, 7.9 mmol) in dioxane (30 ml) were added concentrated sulfuric acid (2.5 g) and water (12 ml) at room temperature and the i reaction mixture was heated at reflux temperature 30 for 24 hours. It was concentrated in vacuo and the residue was combined with another batch of the same material and dissolved in ethyl acetate (400 ml). The resulting solution was washed with IN sodium hydroxide (50 ml) followed by water (50 ml) and 35 dried over anhydrous magnesium sulfate and 24 5 3 0 0 HA488b 47 concentrated in vacuo to give the title A compound (3.7 g) as an oil: *H NMR (CDC13) 6 7.74 (s, 1 H), 7.42 (dd, J = 2.0 & 6.0 Hz, 1 H), 6.82 (d, J = 8.0 Hz, 1 H), 3.65 (d, J = 10.0 Hz, 1 H), 3.36 (d, J = 5 10.0 Hz, 1 H), 1.53 (s, 3 H), 1.23 (s, 3 H).

B. (3R-trans)-N"-Cyano-N-(6-cyano-3,4-dihydro- 3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4- yl)-N1-phenylquanidine To a solution of N-cyano-N'-phenylthiourea (3.9 g, 21.9 nunol) and the title A compound (3.68 g, 16.9 mmol) in dimethylformamide (20 mL) under argon, l-(3-dimethylaminopropyl)-2-ethylcarbodi-imide hydrochloride (4.2 g, 21.9 mmol) was added at 15 room temperature. The reaction mixture was stirred at room temperature for 2 hours and then partitioned between IN hydrochloric acid and ethyl acetate. The organic phase was separated and the aqueous phase was reextracted with ethyl acetate. The combined 20 extracts were washed with water, aqueous sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the crude product was triturated with ethyl acetate-ether to give a colorless solid (3.5 g). The crude 25 product was purified by flash chromatography on silica gel eluting with ethyl acetate/hexanes (7:3) and the solid, obtained after evaporation of the solvent, was triturated with ether to give the title compound (1.8 g) as a colorless solid, m.p. 215-217°C, 30 |>D]25 = +34.8° (c = 0.417, MeOH): XH NMR (CDCl3/DMS0-d6) 6 8.8 (s, 1 H), 7.6 (S, 1 H), 7.44 (d, J = 8.0 Hz, 1 H), 7.35 (d, J = 5.0 Hz, 4 H), 7.22 (m, 1 H), 6.85 (d, J = 8.8 Hz, 1 H), 6.7 (br s, 1 H), 5.0 (t, J = 9.0 Hz, 1 H), 3.72 (br d, J = 24 5 3 0 0 HA488b 48 .3 Hz, 1 H), 1.48, 1.18 (s, 3 H each); l3C NMR (CDCl3/DMSO-d6) 159.6, 156.5, 136.6, 132.5, 129.2, 125.7, 124.1, 123.7, 118.9, 118.1, 117.2, 103.4, 80.3, 72.8, 52.4, 26.4, 18.6; IR (KBr) 2226, 2179, 1609, 1582, 1491, 1267 cm"1.

Analysis calc'd for C20H19N5O2*0.45 H20: C, 65.01; H, 5.42; N, 18.95; Found: C, 65.18; H, 5.47; N, 18.51.

Example 20 is an alternate procedure to Example 18 and the procedure of this Example 20 is preferred. Additionally, the 3S, 4R enantiomer of Example 20 is the preferred compound of the present invention- Example 20 (3S-trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl) -N1 -phenylquanidine A. [3S-[3a,40(S*)]]-N-(6-Cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-a-hydroxybenzeneacetamide and [3R-[3a,40(R*)]]-N-(6-Cyano-3,4-dihydro-3-hydroxy-2-, 2-dimethyl-2H-l-benzopyran-4- yl) -a -hydroxybenzeneacetamide To a solution of (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (prepared according to Evans et al., J. Med. Chem., 24 5 3 HA488b 49 1983, 26, 1582 and J. Med. Chem., 1986, 29, 2194) (1.64 g, 7.5 mmol), R(-)-mandelic acid (1.14 g, 7.5 mmol), hydroxybenzotriazole hydrate (1.0 g, 7.5 mmol) in dimethylformamide (15 ml) at 0°C was 5 added dicyclohexylcarbodiimide (1.55 g, 7.5 mmol) at room temperature. The reaction mixture was allowed to stir at room temperature for 20 hours and then cooled in an ice bath. The solid was removed by filtration and the filtrate was 10 concentrated in vacuo. The residue was dissolved in 5% methanol in chloroform and washed with 1 N sodium hydroxide, 1 N hydrochloric acid, brine followed by drying over anhydrous.magnesium sulfate. After removing drying agent the solvent 15 was removed in vacuo. The residue was crystallized from ethanol to give [3S-[3a,4p(S*)]]-N- (6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-a-hydroxybenzeneacetamide (0.85 g) as a white solid, m.p. 235-237°C: [aD]25 = 20 -94.9° (c = 1, MeOH); JH NMR (DMS0-d6) 6 8.45 (d, J = 8.0 Hz, 1 H), 7.5 (m, 4 H), 7.3 (m, 2 H), 7.0 (s, 1 H), 6.88 (d, J = 8.0 Hz, 1 H), 6.2 (s, 1 H), 5.57 (d, J = 5.0 Hz, 1 H), 5.0 (s, 1 H), 4.76 (t, J = 9.0 Hz, 1 H), 3.75 (dd, J = 5.0 & 5.0 Hz, 1 H), 25 1.40 (s, 3 H), 1.15 (s, 3 H).

Analysis calc'd for C20H20N2O4: C, 68.17; H, 5.72; N, 7.95; Found: C, 68.00; H, 5.52; N, 7.95.

The residual material recovered from the mother liquor was purified by flash chromatography on silica gel eluting with hexane-ethyl acetate (3:7) and the product was crystallized from 24 5 3 HA488b 50 dichloromethane-isopropyl ether to give [3R-[3a,40(R*)]]-N-(6-Cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-a-hydroxy-benzeneacetamide as a white solid, m.p. 100-102°C (foaming): [aD]25 = +25.6° (c = 1, MeOH): *H NMR (CDC13) 5 7.4 (m, 5 H), 7.26 (t, J = 1.0 Hz, 1 H), 6.97 (d, J = 9.0 Hz, 1 H), 6.83 (d, J = 9.0 Hz, 1 H), 5.16 (s, 1 H), 4.98 (t, J = 9.0 Hz, 1 H), 3.8 (d, J = 5.0 Hz, 1 H), 3.55 (dd, J = 4.0 & 5.0 Hz, 1 H), 1.45 (s, 3 H), 1.2 (s, 3 H).

Analysis calc'd for C2oH2oN204•0.25 H20: C, 67.30; H, 5.78; N, 7.84; Found: C, 67.17; H, 5.87; N, 7.44.

B. (3S-trans)-4-Amino-3,4-dihydro-3-hydroxy- 2,2-dimethyl-2H-l-benzopyran-6-carbonitrile To a solution of [3S-[3a,40(S*)]]-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-a-hydroxybenzeneacetamide, title A compound (6.09 g, 17.0 mmol) in dioxane (60 ml) was added a solution of sulfuric acid (6.0 g) in water (30 ml) at room temperature and the reaction mixture was heated at reflux temperature for 24 hours. It was then concentrated in vacuo and the residue was dissolved in ethyl acetate. The organic layer was washed with IN sodium hydroxide followed by water and dried over anhydrous magnesium sulfate. The solvent was evaporated to give the title B compound as an oil: *H NMR (cdci3) 6 7.74 (s, 1 H), 7.42 (dd, J = 2.0 & 6.0 Hz, 1 H), 6.82 (d, J = 8.0 Hz, 1 H), 3.65 (d, J = 10.0 Hz, 1 H), 3.36 (d, J = 10.0 Hz, 1 H), 1.53 (s, 3 H), 1.23 (s, 3 H). 245300 HA488b 51 C. (3S-trans)-N"-Cyano-N-(6-cyano-3,4-dihydro- 3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N1 -phenylquanidine To a solution of N-cyano-N1-phenylthiourea 5 (2.11 g, 11.9 mmol) and (3S-trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran~6-carbonitrile (2.0 g, 9.1 mmol), title B compound, in dimethylformamide (20 mL) under argon was added 1-(3-dimethylaminopropyl)-2-ethylcarbodiimide 10 hydrochloride (2.23 g, 11.9 mmol) at room temperature. The reaction mixture was stirred at room temperature for 2 hours and then partitioned between IN hydrochloric acid and.ethyl acetate. The organic phase was separated and the aqueous 15 phase was reextracted with ethyl acetate. The combined organic exttacts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the crude product was purified by 20 flash chromatography on silica gel eluting with ethyl acetate/hexanes (7:3) to give a colorless solid which was triturated with ether to yield the title compound (0.35 g), m.p. 215-216°C: [cr]p2S = -33.5° (c = 1, MeOH); XH NMR (DMSO-d6) 6 9.28 (s, 25 1 H), 7.58 (d, J = 8.0 Hz, 3 H), 7.35 (m, 4 H), 7.15 (m, 1 H), 6.90 (d, J = 8.2 Hz, 1 H), 5.92 (br s, 1 H), 4.92 (t, J = 9.0 Hz, 1 H), 3.72 (br d, J = 5.9 Hz, 1 H), 1.41, 1.18 (s, 3 H each); 13C NMR (DMSO-d6) 159.2, 156.3, 137.5, 132.6, 132.5, 129.0 30 124.8, 124.7, 123.6, 119.0, 117.8, 117.0, 102.6, 80.4, 70.9, 51.9, 26.6, 18.6; IR (KBr) 2226, 2179, 1609, 1582, 1491, 1267 cm"1. 24 5 3 0 0 HA488b 52 Analysis calc'd for C2 0HX9N502*0.24 H20: C, 65.26; H, 5.40; N, 19.02; Found: C, 65.62; H, 5.36; N, 18.57.

HPLC: 99.5% by Chiracel OD column/hexanes (80%), isopropanol (20%), formic acid (0.1%).

Example 21 (trans)-4-[2-(Cyanoimino)tetrahydro-1(2H) -pyrimidinyl]-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-»carbonitrile A. (trans)-4-[(3-Aminopropyl)amino]-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile To a suspension of 6-cyano-3,4-expoxy-3,4-dihydro-2,2-dimethyl-2H-benzopyran (prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med. Chem., 1986, 29, 2194) (1.0 g, 5.0 mmol) in ethanol (5.0 mL), 1,3-diamino-propane (2.4 mL, 32.4 mmol) was added at room temperature and the reaction mixture was stirred at room temperature for 36 hours. The solvent was removed under reduced pressure and the residue was dried by use of a vacuum pump for 5 hours to yield the title A compound (1.3 g) as a colorless foam. This material was used for the next step without purification. 4 B. (trans)-4-[2-(Cyanoimino)tetrahydro-1(2H)-pyrimidinyl]-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile To a solution of the title A compound (1.3 g, 4.7 mmol) in ethanol (5 ml) at room temperature, 53 245300 HA488b triethylamine (1.3 mL, 9.4 mmol) was added followed by dimethyl N-cyanodithioiminocarbonate (1.5 g, 9.4 mmol of 90%) with stirring at room temperature. The reaction mixture was heated at 80°C for 3 hours 5 and then cooled to ambient temperature. The solvent was evaporated to give a light yellow foam (1.5 g). This material was taken up in methanol (20 mL) and the resulting suspension was treated with mercuric acetate (2.0 g, 6.1 mmol). The 10 reaction mixture was stirred at room temperature for 2 hours and the solvent was evaporated under reduced pressure. The residue was diluted with water and alkalized to pH ~9.0 wrth 2.5N sodium hydroxide and the product was extracted with 10 15 percent methanolic chloroform (3x). The combined extract was washed with brine whereby a thick emulsion resulted. The two phase mixture was filtered through a celite pad and the organic layer was separated and dried over magnesium sulfate. 20 The solvent was evaporated and the residue was purified by flash chromatography (5% methanol in chloroform) on silica gel to provide a colorless residue (0.5 g) which was crystallized from isopropyl ether-ethyl acetate to yield the title 25 compound as a white powder, m.p. 152-153°C: NMR (DMSO-d6) 6 7.60 (d, J = 7.0 Hz, 1 H), 7.40 (s, 1 H), 7.0 (d, J = 9.0, 1 H), 5.85 (d, J = 5.2 Hz, 1 H), 5.6 (d, J = 10.5 Hz, 1 H), 3.8 (dd, J = 5.0 Hz, 1 H), 3.2 '.(m, 4 H), 2.9 (br d, 1H), 1.54, 30 1.26 (s, 3 H each); 13C NMR (DMS0-d6) 164.5, 156.8, 133.2, 131.6, 118.9, 118.2, 118.0, 103.1, 80.4, 67.3, 51.2, 40.3, 26.6, 18.6; IR (KBr) 1268.7, 1316.8, 1402.2, 1489.5, 1558.1, 1580.4, 2174.7, 3421.3 cm"1. 245300 HA488b 54 Analysis calc'd for C17Hi9Ns02*0.42 H20: C, 61.33; H, 6.01; N, 21.04; Found: C, 61.31; H, 6.02; N, 21.06.

Example 22 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3~hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-(4-pyridinylmethyl)quanidine A suspension of (trans)-4[[(cyanoimino)-phenoxymethyl]amino]-3,4-dihydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 2.76 mmol), compound of Example 7, part A, in isopropanol (5 15 ml) was treated at room temperature with 4-(amino-methy1)pyridine (1.0 ml). The reaction mixture was allowed to stir at room temperature for 4 hours and then heated at reflux temperature for 16 hours. The reaction mixture was cooled to ambient 20 temperature and the precipitated solid was filtered off. The product was recrystallized from ethyl acetate to give the title compound (0.76 g) as a colorless solid, m.p. 156-158°C: *H NMR (DMSO-dg) 6 8.53 (d, J = 6.0 Hz, 2 H), 7.9 (m, 1 25 H), 7.59 (dd, J = 3.0 & 6.0 Hz, 1 H), 7.44 (s, 2 H), 7.31 (d, J = 6.0 Hz, 2 H), 6.91 (d, J = 9 0 Hz, 1 H), 5.9 (s, 1 H), 4.87 (m, 1 H), 4.48 (t, J = 2.0 & 6.0 Hz, 2 H), 3.7 (m, 1 H), 1.99 (s, 3 H), 1.18 (s, 3 H); 13C'NMR (DMSO-d6) 160.4, 156.2, 30 149.4, 132.6, 132.3, 124.7, 121.7, 117.8, 117.4, 102.6, 80.4, 71.0, 51.5, 43.4, 26.5, 18.6; IR (KBr) 1125.2, 1490.2, 1524.1, 1577.8, 1611.3, 2170.4, 2224.9, 3429.7 cm"1. 245300 HA488b 55 Analysis calc'd for C2oH2oN60z*0.2 H20: C, 63.22; H, 5.41; N, 22.12; Found: C, 63.42; H, 5.17; N, 21.92.

Example 23 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N1-(3-pyridinyl-methyl)quanidine A suspension of (trans)-4-[[(cyanoimino)-phenoxymethyl ] amino ] -3,4-dihydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (l'.O g, 2.76 mmcl), compound of Example 7, part A, in isopropanol (5 15 ml) was treated at room temperature with 3-(amino-methyl)pyridine (1.0 ml). The reaction mixture was allowed to stir at room temperature for 4 hours and then heated under reflux for 16 hours. The reaction mixture was concentrated in vacuo and 20 the resulting solid was crystallized from ethyl acetate to give the title compound (0.72 g) as a colorless solid, m.p. 226-228°C: 1H NMR (DMSO-dg) 6 8.55 (s, 1 H), 8.49 (d, J = 2.0 Hz, 2 H), 7.85 (ffi, 1 H), 7.75 (d, J = 8.0 Hz, 1 H), 7.59 25 (d, J = 8.0 Hz, 1 H), 7.40 (m, 3 H), 6.91 (d, J = 8.0 Hz, 1 H), 5.85 (s, 1 H), 4.82 (m, 1 H), 4.48 (m, 2 H), 3.74 (m, 1 H), 1.40 (s, 3 H), 1.17 (s, 3 H); 13C NMR 160.43, 156.2, 148.6, 148.2, 134.6, 134.2, 132.7, 132.2, 124.8, 123.4, 118.9, 117.9, 30 117.5, 102.6, 80.4, 71.0, 51.5, 42.1, 26.6, 18.7; IR (KBr) 1125.2, 1490.1, 1524.1, 1577.8, 1611.3, 2170.4, 2224.9, 3429.7 cm"1. 24 5 3 0 0 HA488b 56 Analysis calc'd for C2oH2oN602•0.17 H20: C, 63.22; H, 5.41; N, 22.12; Found: C, 63.08; H, 5.32; N, 22.38.

Example 24 (trans)-N"-Cyano-N-(6-ethynyl-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl) -N' -phenylquanidine A. 1-((1,l-Dimethyl-2-propynyl)oxy)-4- iodobenzene A solution of 3-chloro-3-methyl-l-butyne (10.0 g, 97.9 mmol), 4-iodophenol (15.0 g, 68.4 15 mmol), sodium hydroxide (3.90 g, 97.5 mmol) and tetrabutylammonium hydrogen sulfate (9.33 g, 27.5 mmol; in methylene chloride (50 mL) and water (50 mL) was stirred for 19 days at room temperature. After separating the two layers, the organic layer 20 was washed with 1 N sodium hydroxide followed by water, dried over magnesium sulfate and concentrated in vacuo. The residue was dissolved in ethyl acetate and washed successively with 1 N hydrochloric acid, 1 N sodium hydroxide, water, 25 brine and dried over anhydrous magnesium sulfate. After removing drying agent, the solvent was removed in vacuo. The crude product was purified by flash chromatography on silica gel eluting with toluene/hexane (1:10) to give the title compound 30 as an oil (5.78 g, 20.2 mmol) in 30% yield: 1H NMR (CDC13) 6 7.56 (d, J = 8.7 Hz, 2H), 6.98 (d, J = 245300 HA488b 57 8.8Hz, 2H), 2.56 (s, 1H), 1.63 (s, 6H); 13C NMR (CDC13) 5 155.4, 137.8, 123.5, 86.0, 85.6, 74.3, 72.6, 29.5.

B. 2,2-Dimethyl-6-iodo-2H-l-benzopyran The title A compound (3.91 g, 13.7 mmol) was heated in an oil bath at 170° for 2 hours. After cooling, the crude product was purified by 10 flash chromatography on silica gel eluting with toluene/hexane (1:20) to give the title compound as an oil (3.26 g, 11.4 mmol) in 83% yield: XH NMR (CDCI3) 6 7.34 (dd, Jj = 1.8, J2 - 2.4 Hz, 1H), 7.24 (d, J = 0.9 Hz, 1H), 6.52 (d, J = 8.8 Hz, 15 1H), o.21 (d, J = 10.0 Hz, 1H), 5.58 (d, J = 10.0 Hz, 1H), 1.40 (s, 6H); 13C NMR (CDCl3) 6 152.8, 137.5, 134.7, 131.6, 123.6, 121.1, 118.6, 82.4, 76.4, 27.9.

C. 2,2-Dimethyl-6-(trimethylsilyl)ethynyl)- 2H-l-benzopyran A solution of the.title B compound (1.32 g, 4.61 mmol), trimethyl((trimethylstannyl)ethynyl)-silane (1.60 g, 5.69 mmol), lithium chloride (0.62 25 g, 14.6 mmol) and tetrakis(triphenylphosphine) palladium (0.69 g, 0.60 mmol) in dioxane (16.5 mL) was stirred under argon for 5 hours in an oil bath at 65°. The reaction mixture was cooled to room temperature and concentrated in vacuo to give a 30 residue that was combined with the material prepared in a similar manner on a 2.42 mmol scale. The combined material was rinsed with toluene/hexane (1:10) and the filtrate was 24 5 3 0 HA488b 58 concentrated in vacuo. The crude product was purified by flash chromatography on silica gel eluting with toluene/hexane (1:10) to give the title C cmpound as an oil (1.82 g, 7.00 mmol) in 5 100% yield: *H NMR (CDC13) 6 6.98 (dd, = 2.3, J2 = 8.2 Hz, 1H), 6.87 (d, J = 1.8 Hz, 1H), 6.44 (d, J = 8.2 Hz, 1H), 6.02 (d, J = 9.4 Hz, 1H), 5.38 (d, J = 10.0 Hz, 1H), 1.20 (s, 6H), 0.00 (s, 9H); 13C NMR (CDC13) 6 153.4, 133.0,131.2, 10 130.0,121.6, 121.0, 116.3, 115.2, 105.2, 92.1, 76.7, 28.1, 0.1.

Analysis calc'd for C16H20OSi: C, 74.94; H, 7.86; * * Found: C, 75.19; H, 7.61.

D. (cis)-la,7b-Dihydro-2,2-dimethyl-6-((tri- methylsilyl)ethynyl)-2H-oxireno(c)-(1)- benzopyran To a solution of the title C compound (1.37 20 g, 5.34 mmol) and sodium bicarbonate (2.33 g, 27.7 mmol) in methylene chloride (27 mL) and water (27 mL) at 0° was added 3-chloroperoxybenzoic acid (1.51 g of 80-85% purity, 7.01 mmol). After a few minutes of stirring, the ice bath was removed and 25 the reaction mixture was stirred at room temperature for 9 hours. After adding methylene chloride to the reaction mixture, the organic layer was separated and washed with water followed by brine, dried over magnesium sulfate and concentrated in 30 vacuo. The crude product was purified by flash chromatography on silica gel eluting with hexane/ ethyl acetate (10:1) to give recovered starting material (0.47 g) and the title copound as an oil 24 5 3 HA488b 59 (0.53 g, 1.95 mmol) in 36% yield: XH NMR (CDC13) 6 7.24 (d, J = 1.8 Hz, lH), 7.11 (dd, Jx = 1.78, J2 = 2.3 Hz, 1H), 6.49 (d, J = 8.2 Hz, 1H), 3.62 (d, J = 4.1 Hz, 1H), 3.25 (d, J = 4.1 Hz, 1H), 1.34 (s, 5 3H), 1.00 (s, 3H), 0.00 (s, 9H); 13C NMR (CDC13) 6 152.9, 134.1, 133.4, 120.0, 118.1, 103.6, 92.9, 73.6, 62.5, 50.5, 25.6, 22.7, 0.00.

E. (trans)-4-Amino-6-ethynyl-3,4-dihydro-2H- 1-benzopyran-3-o 1 A solution of the title D compound (0.53 g, 1.95 mmol) in ethanol (15 mL) and concentrated aqueous ammonium hydroxide (30 mL') was stirred at room temperature for 4 days. The solvent was 15 removed in vacuo and the residue was purified by flash chromatography on silica gel eluting with hexane/ethyl acetate/methanol (5:5:1) to give a partially purified product. This material was triturated with diethyl ether to give the title 20 compound as a white solid (0.42 g, 1.93 mmol) in 99% yield, m.p. 132-134°C: XH NMR (CDC13) 6 7.62 (s, 1H), 7.38 (dd, Ji = 1.2, J2 = 1.8 Hz, 1H), 6.82 (d, J = 8.2, Hz, 1H), 3.73 (d, J = 10.0 Hz, 1H), 3.45 (d, J = 9.4 Hz, 1 H), 3.10 (s, 1H), 2.56 (br 25 s, 3H), 1.59 (s, 3H), 1.30 (s, 3H); 13C NMR (CDC13) 6 153.0, 132.6, 131.0, 125.7, 117.2, 114.0, 83.6 78.6, 75.9, 75.8, 51.1, 26.9, 18.7. Analysis calc'd for Ci3HlsN02*0.06 H20: C, 71.52; H> 6.98; N, 6.42; Found: C, 71.47; H, 6.95; N, 6.47. 2 4 5 3 0 0 HA488b 60 F. (trans)-N"-Cyano-N-(6-ethynyl-3,4-dihydro- 3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4- yl)-N'-phenylguanidine To a solution of the title E compound 5 (0.150 g, 0.69 mmol) and N-cyano-N1-phenylthiourea (0.180 g, 1.0 mmol) in dimethylformamide (5 mL) was added 1-(3-dimethylaminopropyl)-2-ethyl-carbodiimide hydrochloride (0.200 g, 1.0 mmol) at room temperature. The reaction mixture was 10 stirred overnight at room temperature and the solvent was removed in vacuo. The residue was partitioned between water and ethyl acetate. The organic layer was separated and dried over sodium sulfate. The solvent was removed in vacuo and the 15 residue was purified by flash chromatography on silica gel eluting with hexane/ethyl acetate/ ethanol (30:10:5) to give a partially pure product. This material was triturated with diethyl ether to give the title compound (0.12 g, 20 0.34 rrnol) in 49% yield, m.p. 220-222°C (dec); NMR (CDC13) 6 7.20-7.40 (m, 7H), 6.70 (d, J = 8.2 Hz, 1H), 5.00 (d, J = 10:0 Hz, 1H), 3.67 (d, J = 9.4 Hz, 1H), 3.34 (s, 1H), 1.44 (s, 3H), 1.24 (s, 3H); 13C NMR (CDC13) 6 161.6, 154.6, 138.2, 25 133.7, 132.8 130.5, 127.2, 125.7, 123.9, 118.9, 118.3, 116.0, 84.3, 80.5, 77.2, 74.6, 54.0, 27.1, 18.6.

Analysis calc'd for C2iH2oN402•0.32 H20: C, 68.89; H, 5.68; N, 15.31; Found: C, 69.11; H, 5.55; N, 15.09. 24 5 3 HA488b 61 Example 25 (trans)-N"-Cyano-N-(3,4-dihydro-6-(phenylethynyl)-2H-l-benzopyran-4-yl)-N'-phenylquanidine A. 2,2-Dimethyl-6-(phenylethynyl)-2H-l- benzopyran To a solution of the title B compound from Example 24 (1.69 g, 5.91 mmol) and phenylacetylene (2.0 mL, 18.1 mmol) in diethylamine (30 mL) at room temperature were added bis(triphenylphosphine)-palladium(II)chloride (0.40 g, 0.572 mmol) and copper(I) iodide (0.22 g, 1.41 mmol) under argon atmosphere. After stirring for 1 hour at room temperature, the reaction mixture was concentrated under reduced pressure. The residue was dissolved in ethyl acetate and the insoluble material was filtered. The filtrate was concentrated in vacuo. The residue was again dissolved in toluene/hexane (1:10) and the insoluble material was filtered. The filtrate was concentrated in vacuo and the crude product was purified by flash chromatography on silica gel eluting with toluene/hexane (1:10) to give the title compound as an oil (1.43 g, 5.49 mmol) in 92% yield: XH NMR (CDC13) 6 7.47-7.50 (m, 2H), 7.24-7.31 (m, 4H), 7.14 (d, J = 2.4 Hz, 1H), 6.72 (d, J = 8.2 Hz, 1H), 6.26 (d, J = 10.0 Hz, 1H), 5.58 (d, J = 9.4 Hz, 1H), 1.40 (s, 6H); 13C NMR (CDC13) 6 153 .'2, 132.5, 131.3, 131.2, 129.5, 128.2, 127.8, 123.6, 121.6, 121.1, 116.4, 115.2, 89.4, 87.8, 76.7, 28.0. ? b ^ 1 HA488b 62 B. 2,2-Dimethyl-6-(phenylethynyl)-2H-oxireno- (c)-(1)-benzopyran To a solution of the title A compound (1.14, 4.38 mmol) and sodium bicarbonate (1.86 g, 5 22.1 mmol) in methylene chloride (15 mL) and water (15 mL) at 0° was added 3-chloroperoxybenzoic acid (1.21 g of 80-85% purity, 5.62 mmol). After 5 minutes, the ice bath was removed and the reaction mixture was stirred at room temperature for 8 10 hours. It was diluted with methylene chloride and the organic layer was taken. It was washed with water followed by brine and dried over magnesium sulfate. The solvent was concentrated in vacuo and the material was purified by flash 15 chromatography on silica gel eluting with hexane/ethyl acetate (10:1) to give recovered starting material (0.17 g) and the title compound as an oil (0.74 g, 2.68 mmol) in 61% yield: NMR (CDC13) 6 7.42-7.64 (m, 7H), 6.90 (d, J = 8.8 20 Hz, 1H), 3.99 (d, J = 4.7 Hz, 1H), 3.60 (d, J = 4.7 Hz, 1H), 1.69 (S, 3H), 1.38 (s, 3H); 13C NMR (cdci3) 6 152.8, 133.7, 132.9, 131.4, 128.3, 128.0, 123.4, 120.2, 118.2, 115.9, 88.9, 88.3, 73.6 62.5, 50.6, 48.2, 22.7.

C. (trans)-4-Amino-3,4-dihydro-2,2-dimethyl-6-(phenylethynyl)-2H-l-benzopyran-3-ol A solution of the title B compound (0.71 g, 2.55 mmol) in absolute ethanol (20 mL) and 30 concentrated aqueous ammonium hydroxide (40 mL) was stirred for 7 days and the solvents were removed in vacuo. The crude product was triturated with hexane and diisopropyl ether to give the title compound as a white solid (0.64 g, 35 2.18 mmol) in 86% yield, m.p. 162-164°C; *H NMR 245300 HA488b 63 (COCl3) 6 7.36-7.67 (m, 7H), 6.86 (d, J = 8.2 Hz, 1H), 3.78 (d, J = 10.0 Hz, 1H); 3.48 (d, J = 10.0 Hz, 1H), 2.51 (br s, 3H), 1.62 (s, 3H), 1.32 (s, 3H); 13C NMR (CDC13) 6 152.7, 132.1, 131.4, 130.4, 128.3, 128.0, 125.6, 122.8, 117.3, 115.0, 88.6, 87.1, 78.5, 76.0, 51.2, 26.9, 18.7.

Analysis calc'd for Ci9H1902N-0.28 H20: C, 76.46; H, 6.61; N, 4.69; Found: C, 76.39; H, 6.52; N, 4.76.

D. (trans)-N"-Cyano-N-(3,4-dihydro-6-(phenyl ethynyl )-2H-l-benzopyran-4-yl)-N'-phenyl- quanidine .

To a solution of the title C compound (0.64 15 g, 2.18 mmol) and N-cyano-N'-phenylthiourea (0.56 g, 3.16 mmol) in dimethylformamide (16 mL) was added 1-(3-dimethylaminopropyl)-2-ethyl-carbodiimide hydrochloride (0.60 g, 3.49 mmol) at room temperature. The reaction mixture was stirred at 20 room temperature for 2 days and the solvent was removed in vacuo. The residue was partitioned between ethyl acetate and water. The organic layer was taken and it was washed with water followed by brine, dried over sodium sulfate and 25 concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with hexane/ethyl acetate/ethanol (10:10:1) to give a partially purified material. This material was triturated with diisopropyl ether to give the 30 title compound as a white solid (0.46 g, 1.05 mmol) in 48% yield, m.p. 175-177°C: XH NMR (DMSO-dg) 6 9.42 (s, 1H), 7.82 (d, J = 8.8 Hz, 1H), 7.20-7.75 (m, 14H), 6.88 (d, J = 9.4 Hz, 1H), 5.59 (br s, 1H), 5.02 (dd, Jx = 8.8, J2 = 9.4 Hz, 35 1H), 3.80 (br d, J = 9.4 Hz, 1H), 1.50 (s, 3H), 1.27 (s, 3H); 13C NMR (DMS0-d6) 6 159.5, 153.2, 138.0, 132.2, 131.6, 131.3, 129.3, 129.0, 128.0, 124.9, 124.1, 123.7, 122.9, 117.4, 114.3, 89.7, 88.3, 79.9, 71.6, 52.5, 27.1, 18.8. 24 5 3 0 0 Example 26 (trans)-N"-Cyano-N-(3-4-dihydro-3-hydroxy-2,2-dimethyl-6-nitro-2H-l-benzopyran-4-yl )-N' -phenyl 5 quanidine To a solution of trans-4-araino-3,4-dihydro-3-hydroxy-2,2-dimethyl-6-nitro-2H-l-benzopyran (2.0 g, 8.39 mmoles, prepared according to Evans 10 et al., J. Med. Chem., 1983, 26, 1582 and J. Med. Chem., 1986, 29, 2194) and N-cyano-N'-phenyl thiourea (1.93 g, 10.91 mmoles) in N,N-dimethyl-formamide (10 ml) was added 1-(3-dimethylamino-propyl )-2-ethylcarbodiimide • HC1 (2:09 g, 10.91 15 mmoles). The reaction mixture was stirred for 2 hours under argon at room temperature and partitioned between ethyl acetate and 5% hydrogen chloride solution. The aqueous phase was extracted with ethyl acetate; the combined organic 20 layers were washed successively with distilled water, saturated sodium hydrogen carbonate solution, saturated sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was recovered under vacuum to obtain 2.79 25 g of crude product. This was twice recrystallized from the minimum amount of hot ethanol to obtain 1.01 g of the title compound as an off-white solid. The combined mother liquors were chromatographed on silica eluting with 1:1 ethyl 30 acetate/hexane to afford an additional 0.49 g of product. NMR (DMSO-d6) 6 9.39 (broad s, 1H), 8.07 (s, 1H), 8.03 (d, J = 2.35 Hz, 1H), 7.69 (d, J = 8.21 Hz, 1H), 7.40-7.34 (m, 4H), 7.18-7.14 (m, 24 5 3 0 0 1H), 6.96 (d, J = 8.80 Hz, 1H), 5.96 (broad s, 1H), 4.98 (m, 1H), 3.77 (d, J = 9.39 Hz, 1H), 1.45 (s, 3H)i 1.22 (s, 3H). 13C NMR (DMS0-d6) 6 159.18, 158.14, 140.63, 137.44, 129.06, 124.77, 124.48, 124.33, 123.99, 123.47, 117.54, 116.90, 81.00, 70.60, 51.97, 26.51, 18.62.

Analysis calc'd for ClsH19Ns04: C, 59.83; H, 5.02; N, 18.37; Found: C, 59.60; H, 4.93; N, 18.29.

Example 27 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-15 (4-cyanophenyl)quanidine A. N-Cyano-N1-4-cyanophenylthiourea The suspension of monosodium cyanamide (4.3 g, 67.2 mmol) in absolute ethanol (170 mL) was 20 slowly treated with 4-cyanophenylisothiocyanate (10.75 g, 67.2 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid 25 was filtered and washed with ethanol to give the title A compound (10.0 g), m.p. >250°C.

♦ B. (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N1-(4-cyanophenyl)quanidine The solution of the title A compound (1.2 g, 5.96 mmol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile 245300 (1.0 g, 4.59 mmol, prepared according to Evans et al J. Med. Chem., 1983, 26, 1582 and J. Med. Chem. 1986, £9, 2194) in dimethylformamide (5 mL) under argon was treated with l-(3-dimethylaminopropyl)-5 2-ethylcarbodiimide hydrochloride (1.17 g, 5.96 mmol). The reaction was stirred at room temperature for 2 hours and then partitioned between IN hydrogen chloride and ethyl acetate. The aqueous phase was reextracted with ethyl 10 acetate and the combined extracts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the colorless residue was crystallized from ethyl acetate to yield the 15 title compound (0.52 g), m.p. 261-262°C. NMR (DMSO-dg) 6 8.24 (m, 3H), 7.63 (m, 3H), 6.94 (d, J = 8.7 Hz, 1H), 6.1 (br s, 1H), 4.92 (t, J = 9.0 Hz, 1H), 3.68 (br d, J = 5.2 Hz, 1H)(. 1.44, 1.20 (s, 3H each). 13C NMR (DMS0-d6) 6 158.7, 156.3, 20 145.1, 142.4, 132.9, 124.9, 124.0, 121.2, 119.1, 117.9, 116.3, 102.7, 80.4, 70.9, 51.9V 26,6, 18.6. IR (KBr) 3421.9, 2226.0, 2183.6, 1612.6, 1587.5, 1491.1, 1265.4 cm-1.

Analysis calc'd for C2iH18N602•0.44 H20: 25 C, 63.96; H, 4.82; N, 21.32; Found: C, 64.36; H, 4.65; N, 20.94. 245300 Example 28 (trans)-N"-Cyano-N- (6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N,-5 (4-methoxyphenyl) quanidine A. N-Cyano-N1-(4-methoxy)phenylthiourea The suspension of monosodium cyanamide (1.95 g, 30.3 mmol) in absolute ethanol (50 mL) 10 was slowly treated with 4-methoxyphenylisothio-cyanate (5.0 g, 30.3 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid 15 was filtered and washed with ethanol to give the title A compound (5.4 g), m.p. >250°C.

B. (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2 ,2-dimethyl-2H-l-benzopyran-4-yl )- N'- (4-methoxyphenyl)quanidine The solution of the title A compound (1.23 g, 5.96 mrriol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.59 mmol, prepared according to Evans et 25 al., J. Med. Chem., 1983, 26, 1582 and J. Med. I Chem. 1986, 29, 2194) in dimethylformamide (5 mL) under argon was treated with l-(3-dimethyiamino-propyl)-2-ethylcarbodiimide hydrochloride (1.17 g, 5.96 mmol). The reaction was stirred at room 30 temperature for 2 hours and then partitioned between IN hydrogen chloride and ethyl acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with 24 5 30 0 water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the colorless residue was crystallized from ethyl acetate to yield the 5 title compound (0.53 g), m.p. 228-229°C. NMR (DMSO-de) 6 9.15 (s, 1H), 7.66 (m, 2H), 7.33 (d, J = 9.4 Hz, 3H), 6.99 (t, J = 8.8 & 8.2 Hz, 3H), .88 (br s, 1H), 4.97 (t, J = 8.8 & 9.4 Hz, 1H), 3.83 (s, 3H), 3.38 (m, H), 1.48, 1.25 (s, 3H 10 each). 13C NMR (DMS0-d6) 6 159.6. 157.1, 156.2, 132.5, 132.3, 131.6, 129.6, 126.6, 125.0, 117.8, 114.2, 102.5, 80.4, 70.6, 55.2, 51.6, 26.6, 18.5.

IR (KBr) 2978.3, 2179.7, 1579.8, 1491.1, 1244.2 cm"1.

Analysis calc'd for C2iH2iN503: C, 64.43; H, 5.41; N, 17.90; Found: C, 64.12; H, 5.36; N, 17.82. • Example 29 N"-Cyano-N-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-phenylguanidine A. 6-Cyano-3,4-dihydro-2,2-dimethyl-2H-l- benzopyran A solution of 6-cyano-2,2-dimethyl-2H-l-benzopyran (5.5 g, 29.7 mmoles, prepared according to Evans et al. , J. Med. Chem. , 1983, 2j6, 1582 and ) J. Med. Chem. 1986, 29, 2194) in anhydrous ethanol 30 (40 ml) was treated with palladium on carbon (0.35 g) and stirred under hydrogen gas for 2 hours. The catalyst was filtered through celite and the. filter cake washed wi'th ethyl acetate. The 245300 filtrate was concentrated under vacuum to obtain 5.71 g of a yellow oil. The crude product was dissolved in ethyl acetate (60 ml) and washed successively with 5% hydrogen chloride solution 5 (60 ml), saturated sodium hydrogen carbonate solution (60 ml), saturated sodium chloride solution (60 ml) and dried over anhydrous magnesium sulfate. The solvent was recovered under vacuum to yield 5.14 g of the title A 10 compound as a yellow solid (m.p. 30-31°C) which was used in the next step without further purification. *H NMR (CDC13) 6 7.37 (s, 1H), 7.34 (s, 1H), 6.80 (d, J = 8.8 Hz, 1H), 2.78 (dd, 2H), 1.80 (dd, 2H), 1.35 (s, 6H). 13C NMR (CDC13) 6 157.95, 133.82, 15 131.34, 122.07, 119.53, 118.24, 102.66, 75.76, 32.13, 26.81, 22.06.

Analysis calc'd for C12H13N0: C, 76.98; H, 7.00; N, 7.48; Found: C, 77.03; H, 7.02; N, 7.58.

B. 4-Bromo-6-cyano-3,4-dihydro-2,2-dimethyl- 2H-l-benzopyran To a solution of the title A compound (6.40 g, 34.18 mmoles) in carbon tetrachloride (90 ml) 25 was added N-bromosuccinimide (6.69 g, 37.6 mmoles, 1.1 eq.). The solution was purged with argon. A solution of azobisisobutyronitrile (0.4 g, 3.42 mmoles) in carbon tetrachloride (10 ml) was added; the reaction was heated at reflux for 1/2 hour 30 with irradiation (high intensity visible light).

The reaction mixture was concentrated under vacuum and the residue was dissolved in 75 ml ethyl acetate. The solution was washed successively 24 5 3 0 0 with distilled water (4 x 75 ml), saturated sodium hydrogen carbonate solution (75 ml), saturated sodium chloride solution (75 ml), and dried over anhydrous magnesium sulfate. The solvent was 5 recovered under vacuum to obtain 9.51 g of an orange waxy solid which was triturated with cold pentane to provide 7.19 g of a beige solid. This was crystallized from ca. 25 ml of ethyl acetate in hexane (10:90) to yield 4.60 g of the title B 10 compound as off-white needles, m.p. 94-95°C. The mother liquors were combined and chromatographed on silica gel eluting with hexane/ethyl acetate (19:1) to afford an additional 2.26 g of product. JH NMR (CDC13) 6 7.86 (d, J = 1.17 Hz, 1H), 7.42 15 (dd, J = 1.76 and 8.79 Hz, 1H), 6.82 (d, J = 8.80 Hz, 1H), 5.35 (dd, 1H), 2.45 (m, 2H), 1.51 (s, 3H), 1.31 (S, 3H). 13C NMR (CDC13) 6 156.71, 136.25, 133.21, 122.61, 118.87, 103.81, 76.54, 43.57, 40.34, 28.36, 25.45.

Analysis calc'd for C12H12NBrO: C, 54.16; H, 4.54; N, 5.26; Br, 30.02; Found: C, 54.55; H, 4.62; N, 5.46; Br, 29.86.

C. 4-Azido-6-cyano-3,4-dihydro-2,2-dimethyl- 2H-1-benz opyran A solution of the title B compound (6.73 g, 25.29 mmoles) in dry N,N-dimethylformamide (100 ml) was treated with sodium azide (3.79 g,, 50.57 mmoles, 2 eq.) and stirred at room temperature 30 under argon for 4 hours. The reaction mixture was partitioned between 100 ml ethyl acetate and 200 * ml distilled water. 'The organic layer was separated and the aqueous layer was extracted with 2 4 5 3 0 0 100 ml of ethyl acetate. The combined organics were washed successively with distilled water, saturated sodium hydrogen carbonate solution, saturated sodium chloride solution and dried over 5 anhydrous magnesium sulfate. The solvent was evaporated under vacuum to obtain 5.62 g of orange gum which was triturated with pentane to provide 4.50 g of the title C compound as an off-white solid, m.p. 63-64°C. *H NMR (CDC13) 6 7.69 (s, 10 1H), 7.46 (d, J = 8.80 Hz, 1H), 6.86 (d, J = 8.21 Hz, 1H), 4.59 (dd, J = 6.45 and 2.34 Hz, 1H), 2.24 (m, 1H), 2.01 (m, 1H), 1.49 (s, 3H), 1.36 (s, 3H). 13C NMR (CDC13) 6 157.66, 133.79, 133.41, 121.20, 119.24, 104.21, 76.80, 53.73, 38.30, 15 28.97, 26.29.

D. 4-Amino-6-cyano-3,4-dihydro-2,2-dimethyl- 2H-l-benzopyran A solution of the title C compound (2.00 g, 20 8.77 mmole) in absolute ethanol (50 ml) was treated with 10% palladium on carbon (0.25 g) and stirred under hydrogen gas for 1.25 hours at room temperature. The reaction mixture was filtered to remove the catalyst. The filtrate was acidified 25 to pH 1-2 with concentrated hydrogen chloride (0.85 ml) and concentrated under vacuum to a white solid. The crude amine • hydrogen chloride was dissolved in 100 ml distilled water and extracted with ethyl acetate (discarded). The aqueous layer 30 was adjusted to pK 11-12 with 50% sodium hydroxide solution and extracted with ethyl acetate. The extracts were washed with saturated sodium chloride solution and dried over sodium sulfate. 2 4 5 3 The solvent was evaporated under vacuum to provide 1.542 g of the title D compound as a yellow oil which solidified upon standing. The product was used in the next step without further 5 purification. *H NMR (DMSO-d6) 6 8.01 (s, 1H), 7.51 (d, J = 8.21 Hz, 1H), 6.82 (d, J = 8.21 Hz, 1H), 3.86 (dd, 1H), 2.07 (dd, J = 5.87 and 13.49 Hz, 1H), 1.56 (m, 1H), 1.39 (s, 3H), 1.24 (s, 3H). 13C NMR (DMSO-ds) 6 156.82, 132.51, 131.59, 10 129.40, 119.47, 117.45, 101.70, 76.99, 43.13, 42.47, 29.39, 24.70.

E. N"-Cyano-N- (6-cyano-3,4-dihydro-2,2-dimethyl- 2H-l-benzopyran-4-yl)-N'-phenylquanidine A solution of the title D compound (1.3 g, 6.43 mmoles), N-cyano-N'-phenylthiourea (1.48 g, 8.36 mmoles) and l-(3-dimethylaminopropyl)-2-ethyl-carbodiimide • HCl (1.60 g, 8.36 mmoles) in N,N-dimethylformamide (6.5 ml) was stirred at room 20 temperature under argon for two hours. The reaction mixture was partitioned between ethyl acetate and a 5% hydrogen chloride solution. The aqueous layer was extracted with ethyl acetate. The combined organics were washed with distilled 25 water, saturated sodium hydrogen carbonate solution, saturated sodium chloride solution, dried over sodium sulfate, and concentrate^ in vacuo to recover 1.67 g of an off-white solid.

The crude material was chromatographed on silica 30 gel eluting with hexane/ethyl acetate (1:1). Like fractions were combined and evaporated to yield 1.24 g of an off-white solid. This was recrystallized from the minimum amount of hot 24 5 300 ethanol to obtain 780 mg of the title compound as a white solid, m.p, 223-225°C. JH NMR (DMSO-ds) 6 9.31 (s, 1H), 7.68 (s, 1H), 7.56 (m, 2H), 7.34 (m, 4H), 7.18 (m, 1H), 6.89 (d, J = 8.79 Hz, 1H), 5.18 5 (m, 1H), 2.19 (m, 1H), 1.90 (m, 1H), 1.40 (s, 3H), 1.30 (s, 3H). 13C NMR (DMSO-d6) 6 158.26, 157.22, 137.38, 132.51, 132.17, 128.94, 124.94, 124.05, 123.82, 119.09, 118.09, 116.76, 102.10, 77.17, 44.48, 37.57, 29.13, 24.15.

Analysis calc'd for C2oHi9Ns°*°-2 H20: C, 68.83; H, 5.60; N, 20.07; Found: C, 68.96; H, 5.43; N, 19.82.

Example 30 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl) -N' - (4-nitro-phenyl) quanidine A. N-Cyano-N'-4-nitrophenylthiourea The suspension of monosodixim cyanamide (6.4 g, 100 mmol) in absolute ethanol (170 mL) was slowly treated with (4-nitrophenyl )isothiocyanate (12.5 mL, 104.5 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid was filtered and washed with ethanol to giye the title A compound (13.6 g), m.p. >250°C. 2 4 5 3 B. (trans) -N"-Cyano-N- (6-cyano-3,4-dihydro-3- hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)- N1 - (4-nitrophenyl)guanidine The solution of the title A compound (1.3 g, 5.96 mmol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.59 mmol, prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med.

Chem. 1986, 2£, 2194) in dimethylformamide (5 mL) under argon was treated with l-(3-dimethylamino-propyl)-2-ethylcarbodiimide hydrochloride (1.17 g, 5.96 mmol). The reaction was stirred at room temperature for 2 hours and then partitioned between IN hydrogen chloride and ethyl acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium, sulfate, the solvent was evaporated and the residue was flash chroraatographed on silica gel with a mixture of hexane/ethyl acetate (3:7) followed by chloroform/methanol (8:2) to give 0.6 g of product. The resulting product was triturated with ethyl acetate to yield the title compound as a colorless solid, m.p. 250-251°C (foaming). 1H NMR (DMSO-d6) 6 8.23 (d, J = 8.8 Hz, 1H), 7.88 (d, J = 8.8 Hz, 2H), 7.71 (d, J = 8.8 Hz, 2H), 7.58 (d, J = 7.6 Hz, = 2H), 7.01 (d, J = 8.8 Hz, 1H), 6.10 (br s, 1H)„5.01 (t, J = 8.7 & 9.4 Hz, 1H), 3.79 (m, 1H), 1.51, 1.28 (s, 3H each). 13C NMR (DMSO-d6) 6 158.8, 156.3, 142.9, 133.3, 132.9, 124.2, 122.1, 119.1, 117.9, 105.5, 102.7, 80.4, 70.9, 51.9, 26.6, 18.6. IR (KBr) 3387.2, 2986.0, 2224.1, 2185.5, 1612.6, 1568.2, 1520.0, 1342.5, 1265.4 cm"1.

Analysis calc'd for C20H18N6O4*0.75H20: C, 57.21; H, 4.68; N, 20.02; Found: C, 57.35; H, 4.36; N, 19.71.

Example 31 (trans) -N- (4-Chlorophenyl) -N"-cyano-N- (6-cyano-3,4-dihydro-3 -hydroxy-2,2-dimethyl-2H-l-benzo-pyran-4-yl)guanidine 24 5- 3 0 0 A. N-Cyano-N' - (4-chlorophenyl) thiourea The suspension of monosodium cyanamide (1.9 g, 29.4 mmol) in absolute ethanol (50 mL) was slowly treated with 4-chlorophenylisothiocyanate 15 (5.0 g, 29.4 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid was filtered and washed with ethanol to give the 20 title A compound (5.4 g), m.p. >250°C.

B. (trans) -N- (4-Chlorophenyl) -N" -cyano-N- (6-cyano-3 # 4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl )guanidine The solution of the title A compound (1.26 g, 5.96 mmol) and (tran.s)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.59 mmol, prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med. 30 Chem. 1986, 2Jj), 2194) in dimethylformamide (5 mL) under argon was treated with l-(3-dimethylamino-propyl)-2-ethylcarbodiimide hydrochloride (1.17 g, 5.96 mmol). The reaction was stirred at room 2 4 5 3 0 0 temperature for 2 hours and then partitioned between IN hydrogen chloride and ethyl acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with 5 water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was purified by flash chromatography eluting with mixture of ethyl acetate/hexane (7:3). The solid was triturated 10 with ethyl acetate to yield 0.7 g of the title compound, m.p. 216-218°C. *H NMR (DMSO-d6) 6 9.43 (s, 1H), 7.68 (m, 3H), 7.45 (m, 4H), 6.95 (d, J = 8.8 Hz, 1H), 5.99 (br s, 1H), 4.98 (t, J = 9.4 & 8.8 Hz, 1H), 3.79 (m, 1H), 1.50, 1.27 (s, 3H 15 each). 13C NMR (DMSO-d6) 6 159.1, 156.2, 136.5, 132.6, 132.5, 128.8, 125.5, 124.6, 119.0, 117.8, 116.8, 102.6, 80.4, 70.9, 51.9, 26.5, 18.5. IR (KBr) 3400.7, 2226.0, 2181.6, 1606.8, 1575.9, 1491.1, 1267.3 cm"1.

Analysis calc'd for C20H18C1N502: C, 60.68; H, 4.56; N, 17.70; Cl, 8.96; Found: C, 60.40; H, 4.70; N, 17.55; CJ, 8.68.

Example 32 (trans )-N"-Cyano-N- (6-cyano-3,4-diiiydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyr&n-4-yl )-N' -(2-pyridinylmethyl) guanidine A suspension of the title A compound of Example 7 (1.0 g, 2.76 mmol) in isopropanol (5 ml) was treated at room temperature with 2-(aminomethyl)-pyridine (1.0 ml). The reaction mixture was 24 5 3"0 0 allowed to stir at room temperature for 4 hours and then heated under reflux for 16 hours. It was concentrated in vacuo and purified by flash chromatography eluting with ethyl acetate (2 L) 5 followed by 10% methanol in chloroform (1 L) to yield 0.8 g of a colorless residue which was triturated from isopropyl ether to give the title compound (0.54 g) as a white solid, m.p. 202-203°C. *H NMR (DMSO) 6 8.59 (d, J = 7.4 Hz, 10 1H), 7.79 (m, 1H), 7.60 (m, 2H), 7.36 (m, 2H), 6.91 (d, J = 8.8 Hz, 1H), 5.86 (s, 1H), 4.87 (br s, 1H), 4.48 (m, 2H), 3.73 (br s, 1H), 1.40 (s, 3H), 1.18 (s, 3H). 13C NMR 6 160.8, 156.2, 148.8, 136.8, 132.8, 132.7, 124.8, 122.3, 121.2, 119.2, 15 117.8, 102.6, 80.4, 70.8, 51.4, 45.8, 26.6, 18.7. IR (KBr) 1439.3, 1488.6, 1592.9, 2172.4, 2226.4, 2938.9, 2980.9, 3437.2 cm"1.

Analysis calc'd for C20H20N602*0.2 H20: C, 63.22; H, 5.41; N, 22.12; Found: C, 63.51; H, 5.36; N, 21.81.

Example 33 (trans)-N-(2-Chlorophenyl)-N"-cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzo-pyran-4-yl)guanidine 4 A. N-Cyano-N'-(2-chlorophenyl)thiourea The suspension of monosodium cyanamide (1.9 g, 29.4 mmol) in absolute ethanol (50 mL) was slowly treated with 2-chlorophenylisothiocyanate (5.0 g, 29.4 mmol). The reaction was allowed to 24 5 3 0 0 stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid was filtered and washed with ethanol to give the 5 title A compound (6.0 g), m.p. 253-255°C.

B. (trans) -N- (2-Chlorophenyl) -N"-cyano-N- (6- cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl- 2H-l-benzopyran-4-yl) quanidine The solution of the title A compound (1.26 g, 5.96 mmol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.59 mmol, prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med. 15 Chem. 1986, 29, 2194) in dimethylformamide (5 mL) under argon was treated with l-(3-dimethylamino-propyl)-2-ethylcarbodiimide hydrochloride (1.17 g, 5.96 mmol). The reaction was stirred at room temperature for 2 hours -and then partitioned 20 between IN hydrogen chloride and ethyl acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was 25 evaporated and the residue was crystallized from ethyl acetate to yield 1.1 g of the title compound, m.p. 239-240°C. 1E NMR (DMSO-de) 6 9.20 (s, 1H), 7.63 (d, J = 8.0 Hz, 2H), 7.55 (d, J = 10.0 Hz, 2H), 7.38 (m, 2H), 6.92 (d, J = 9^.0 Hz, 30 1H), 5.8 (br s, 1H), 4.91 (t, J = 9.4 & 8.8 Hz, 1H), 3.68 (m, 1H), 1.39, 1.17 (s, 3H each). 13C NMR (DMSO-ds) 6 159.3., 156.3, 132.6, 129.8, 128.0, 124.7, 119.0, 117.9, 116.7, 102.6, 80.5, 26.6, 18.6. IR (KBr) 3432.4, 2982.6, 2225.3 2187.9, 1611.0, 1588.7, 1491.4, 1448.1, 1267.9 cm"1. Analysis calc'd for C20Hi8C1NS02•0.33 H20: C, 59.79; H, 4.68; N, 17.43; Cl, 8.82; Found: C, 60.11; H, 4.79; N, 17.21; Cl, 9.04.

Example 34 (trans)-N-(3-Chlorophenyl)-N"-cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzo-pyran-4-yl)guanidine A. N-Cyano-N'-(3-chlorophenyl)thiourea The suspension of monosodium cyanamide (1.9 g, 29.4 mmol) in absolute ethanol (50 mL) was slowly treated with 3-chlorophenylisothiocyanate (5.0 g, 29.4 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid was filtered and washed with ethanol to give the title A compound (5.4 g), m.p. 258-260°C.

B. (trans)-N-(3-chlorophenyl)-N"-cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl- 2H-l-benzopyran-4-yl)guanidine The solution of the title A compound (1.26 g, 5.96 mmol) and (trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.59 mmol, prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med.

Chem. 1986, 29, 2194)' in dimethylformamide (5 mL) 24 5 3 0 0 under argon vas treated with l-(3-dimethylamino- propyl)-2-ethylcarbodiimide hydrochloride (1.17 g, .96 mmol). The reaction was stirred.at room temperature for 2 hours and then partitioned between IN hydrogen chloride and ethyl acetate.

The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated in vacuo and the residue was crystallized from ethyl acetate to yield 0.9 g of the title compound, m.p. 243-244°C. JH NMR (DMS0-d6) 6 9.42 (s, 1H), 7.80 (d, J = 8.8 Hz, 1H), 7.61 (d, J = 8.8 Hz, 2H), 7.31 (m, 3H), 6.91 (d, J = 8.8 Hz, 1H), 5.90 (br s, 1H), 4.98 (t, J = 9.4 & 8.8 Hz, 1H), 3.69 (m, 1H), 1.41, 1.18 (s, 3H each). 13C NMR (DMSO-d6) 6 159.0, 156.3, 139.3, 133.1, 132.7, 130.5, 124.5, 124.3, 123.1, 121.9, 119.1, 117.9, 116.8, 102.7, 80.4, 71.0, 52.0, 26.6, 18.6. IR (KBr) 3422.4, 2980.7, 2226.5, 2181.8, 1609.3, 1575.3, 1490.1, 1385.6, 1268.1 1126.5 cm"1.

Analysis calc'd for C2oHi8ClN502*0.08 H20: C, 60.46; H, 4.61; N, 17.63; Cl, 8.92; Found: C, 60.11; H, 4.42; N, 17.98; Cl, 9.13.

Example 35 (trans)-N-(4-Fluorophenyl)-N"-cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzo- pyran-4-yl)guanidine » A. N-Cyano-N'-(4-fluorophenyl)thiourea The suspension of monosodium cyanamide (2.1 g, 32.6 mmol) in absolute ethanol (50 mL) was 24 5 3 0 0 slowly treated with 4-fluorophenylisothiocyanate (5.0 g, 32.6 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was 5 cooled to room temperature and the colorless.solid, was filtered and washed with ethanol to give the title A compound (4.1 g), m.p. >270°C.

B. (trans)-N-(4-fluorophenyl)-N"-cyano-N-(6-10 cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl- 2H-l-benzopyran-4-yl)guanidine The solution of the title A compound (1.15 g, 6.0 mmol) and (trans)-4-amino-3/4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile 15 (1.0 g, 4.59 mmol, prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med.

Chem. 1986, 29, 2194) in- dimethylformamide (5 mL) under argon was treated'with l-(3-dimethylamino-propyl )-2-ethylcarbodiimide hydrochloride (1.15 g, 20 6.0 mmol). The reaction was stirred at room temperature for 2 hours and then partitioned between IN hydrogen chloride and ethyl acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with 25 water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was triturated with ethyl acetate to yield 0.8 g of the title compound, m.p. 207-208°C. *H NMR (DMSO-d6) 6 9.29 30 (s, 1H), 7.60 (m, 3H), 7.37 (m, 2H), 7.23 (m, 2H), 6.90 (d, J = 8.8 Hz, i.H), 5.90 (br s, 1H), 4.90 (t, J = 9.4 & 8.8 Hz, 1H), 3.69 (m, 1H), 1.40, 1.17 (s, 3H each). 13C NMR (DMSO-d6) 6 159.4, 2 4 5 3 0 0 156.3, 133.6, 132.7, 132.5, 126.7, 126.6, 124.8, 119.1, 117.9, 115.8, 115.5, 102.6, 80.4, 70.8, 51.8, 26.6, 18.6. IR (KBr) 3412.9, 2980.5, 2226.9, 2179.4, 1611.4, 1585.5, 1509.9, 1490.6, 1385.4, 5 1268.2 cm"1.

Analysis calc'd for C20H18FNS02*0.15 H20: C, 62.86; H, 4.83; N, 18.32; F, 5.01; Found: C, 62.89; H, 4.80; N, 18.29; F, 4.84.

Example 36 (trans)-N"-cyano-N-[3-(Acetyloxy)-6-cyano-3,4-dihydro-2,2-dimethyl-2H-l-benzopyran-4yl ] -N' -phenyl guanidine The solution of the title compound from Example 3 (2.52 g, 6.98 mmoles) and acetic anhydride (1.0 g, 9.8 mmoles) in pyridine (25 ml) was stirred for 60 hours at. room temperature. The crude reaction mixture was partitioned between 20 ethyl acetate and 5% aqueous hydrogen chloride.

The organic layer was washed with distilled water, saturated sodium hydrogen carbonate solution, saturated sodium chloride splution, and dried over anhydrous magnesium sulfate. The solvent was 25 recovered under vacuum to obtain 2.97 g of a white solid. The crude reaction product was recrystallized from ethanol in two crops to obtain 2.24 g of 4 the title compound as a pure white solid, m.p. 239-240°C. *H NMR (DMS0-d6) 6 9.36 (s, 1H), 7.63 30 (m, 3H), 7.35 (m, 2HJ., 7.20 (m, 3H), 6.97 (d, J = 8.80 Hz, 1H), 5.23 (m, 2H), 2.17 (s, 3H), 1.34 (s, 3H), 1.25 (s, 3H) . 13C NMR (DMSO-d6) 6 169.69, 158.69, 155.75, 136.95, 132.94, 132.66, 129.03, 2 4 5 3 0 0 -8 3- 125.28, 124.25, 123.79, 118.86, 118.09, 116.62, 103.31, 78.43, 72.07, 49.49, 25.85, 20.67, 19.54. Analysis calc'd for C22H2iNs03: C, 65.50; H, 5.25; N, 17.36; Found: C, 65.54; H, 5.27; N, 17.36.

Example 37 (3S- trans) -N"-Cyano-N- (6-cyano-3,4-dihydro-3-10 hydroxy-2,2-dimethyl-2H-l-benzopyr an-4-yl)-N' -(4-fluorophenyl) quanidine The solution of N-cyano-N'-(4-fluorophenyl)-thiourea (1.15 g, 6.0 mmol, prepared according to 15 Example 35, part A) and (3S-trans)-4-amino-3,4- dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.5-9 mmol, compound of Example 20, part B) in dimethylformamide (5 mL) under argon was treated with l-(3-dimethylamino-20 propyl )-2-ethylcarbodiimide hydrochloride (1.15 g, 6.0 mmol). The reaction was stirred at room temperature for 2 hours and then partitioned between IN hydrochloric acid and ethyl acetate. . The aqueous phase was reextracted with ethyl 25 acetate and the combined extracts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was flash chromatographed on silica gel eluting with 20% 30 hexanes in ethyl acetate to yield a colorless solid (0.55 g). This solid was triturated with ethyl ether to give the title compound (0.45 g), m.p. 218-219°C: NMR (DMSO-d6 ) 6 9.29 (s, 1H), 2 4 5 3 0 7.60 (m. 3H), 7.37 (m, 2H), 7.23 (m, 2H), 6.90 (d, J = 8.8 Hz, 1H), 5.90 (br s, 1H), 4.90 (t, J = 9.4 & 8.8 Hz, 1H), 3.69 {m, 1H), 1.40, 1.17 (s, 3H each); 13C NMR (DMS0-d6) 159.4, 156.3, 133.6, 5 132.7, 132.5, 126.7, 126.6, 124.8, 119.1, 117.9, 115.8, 115.5, 102.6, 80.4, 70.8, 51.8, 26.6, 18.6; IR (KBr) 3412.9, 2980.5, 2226.9, 2179.4, 1611.4, 1585.5, 1509.9, 1490.6, 1385.4, 1268.2 cm-1. [»D]2 5 = -33.1° (c = 0.483, MeOH).

Analysis calc'd for C2oHi8FNs°2: C, 63.32; H, 4.78; N, 18.46; F, 5.01; Found: C, 63.08; H, 4.94; N, 18.08; F, 4.88.

Example 38 (3S-trans)-N-(4-Chlorophenyl)-N"-cyano-N1-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-'2H-l-benzopyran-4-yl)quanidine The solution of N-cyano-N'-(4-chlorophenyl)- thiourea (1.26 g, 5.96 mmol, prepared according to Example 31, part A) and (3S-trans)-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.59 mmol, compound of 2 5 Example 20, part B) in dimethylformamide (5 mL) under argon was treated with 1-(3-dimethylamino-propyl)-2-ethylcarbodiimide hydrochloride (1.14 g, 5.96 mmol). The reaction was stirred at room temperature for 2 hours and then partitioned 30 between IN hydrochloric acid and ethyl acetate. The aqueous phase was reextracted with ethyl A acetate and the combined extracts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was purified by flas 245300 chromatography eluting with a mixture of ethyl acetate/hexanes (8:2) to yield a solid (0.6 g).

This solid was triturated with ethyl ether to 5 give the title compound (0.48 g), m.p. 170-172°C: XH NMR (DMS0-d6) 6 9.43 (s, 1H), 7.68 (m, 3H), 7.45 (m, 4H), 6.95 (d, J = 8.8 Hz, 1H), 5.99 (br s, 1H), 4.98 (t, J = 9.4 & 8.8 Hz, 1H), 3.79 (m, 1H), 1.50, 1.27 (s, 3H each); 13C NMR (DMS0-d6) 159.1, 156.2, 136.5, 132.6, 132.5, 128.8, 125.5, 124.6, 119.0, 117.8, 116.8, 102.6, 80.4, 70.9, 51.9, 26.5, 18.5; IR (KBr) 3400.7, 2226.0, 2181.6, 1606.8, 1575.9, 1491.1, 1267.3 cm"1. [crD]25 = -32.9° (c = 0.492, MeOH).

Analysis calc'd for C2oHi8C1NS02* 0.17 H20: C, 60.21; H, 4.64; N, 17.55; Cl, 8.89; Found: C, 60.49; H, 4.80; N, 17.27; Cl, 8.90.

Example 39 (3 S-1 rans)-N-(3-Chlorophenyl)-N"-cyano-N'-(6-cyanc-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)quanidine The solution of N-cyano-N'-(3-chlorophenyl)■ thiourea (1.26 g, 5.96 mmol, prepared according to Example 34, part A) and (3S-.tra.ns)-4-amino-3,4- dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6- * carbonitrile (1.0 g, 4.59 mmol, compound of Example 20, part B) in dimethylformamide (5 mL) under argon was treated with 1-(3-dimethylamino-propyl)-2-ethylcarbodiimide hydrochloride (1.17 g, 5.96 mmol). The reaction was stirred at room temperature for 2 hours and then partitioned between IN hydrochloric acid and ethyl acetat^ ^530 The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with 5 water, sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated in vacuo and the residue was flash chromatographed on.silica gel.eluting with 20% hexanes in ethyl acetate to yield a colorless 10 solid (1.0 g). This solid was recrystallized from ethyl acetate to give the title compound (0.36 g), m.p. 239-240°C: *H NMR (DMS0-d6) 6 9.42 (s, 1H), 7.80 (d, J = 8.8 Hz, 1H), 7.61 (d, J = 8.8 Hz, 2H), 7.31 (m, 3H), 6.91 (d, J = 8.8 Hz, 1H), 5.90 (br s, 15 1H), 4.98 (t, J = 9.4 & 8.8 Hz, 1H), 3.69 (m, 1H), 1.41, 1.18 (s, 3H each); 13C NMR (DMSO-d6) 159.0, 156.3, 139.3, 133.1, 132.7, 130.5, 124.5, 124.3, 123.1, 121.9, 119.1, 117.9, 116.8, 102.7, 80.4, 71.0, 52.0, 26.6, 18.6; IR (KBr) 3422.4, 2980.7, 20 2226.5, 2181.8, 1609.3, 1575.3, 1490'.1, 1385.6, 1268.1, 1126.5 cm"1. [aD]25 = -45.8° (c = 0.45, Dimethylformamide) Analysis calc'd for C2oHi8C1N502•0.06 H2O: C, 60.52; H, 4.60; N, 17.65; Cl, 8.93; Found: C, 60.25; H, 4.34; N, 17.92; Cl, 9.29.

Example 40 trans-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-30 2, 2-dimethyl-2H-l-benzopyran-4-yl)-N' - [4-(phenyl-methoxy)phenyl)quanidine A. N-Cyano-N' -(4-phenylmethoxyphenyl)thiourea The suspension of monosodiuxn cyanamide 35 (1.33 g, 20.7 mmol) in absolute ethanol (50 mL) 24 5 3 01 was slowly treated with 4-phenylmethoxyphenyliso-thiocyanate (5.0 g, 20.7 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was 5 cooled to room temperature and the colorless solid was filtered and washed with ethanol to give the title A compound (4.0 g), m.p. >270°C.

B. trans-N"-Cyano-N- (6-cyano-3,4-dihydro-3-10 hydroxy-2,2-dimethyl-2H-l-benzopyran-4- yl) -N' - T4- (phenylmethoxy) phenyl) guanidine The solution of the title A compound (1.68 g, 6.0 mmol) and trans-4-amino-3,4-dihydro-3-hydroxy-2,2-diraethyl-2H-l-benzopyran-6-carbonitrile 15 (1.0 g, 4.59 mmol, prepared according to Evans et al., J. Med. Chem., 1983, 26, 1582 and J. Med. Chem., 1986, 29^, 2194) in dimethylformamide (5 mL) under argon was treated with l-(3-dimethylamino-propyl)-2-ethylcarbodiimide hydrochloride (1.15 g, 20 6.0 mmol). The reaction was stirred at room temperature for 2 hours and then partitioned between 10% citric acid and ethyl acetate and the solid was separated out. The aqueous phase was reextracted with ethyl acetate and the combined 25 extracts were washed with water, sodium bicarbonate and brine. After drying over anhydrous magnesium 4 sulfate, the solvent was evaporated and the residue was combined with previous solid and crystallized from hot ethyl acetate to give the title compound 30 as a colorless solid (1.1 g), m.p. 229-230°C: NMR (DMSO-dg) 6 9.13 (s, 1H), 7.62 (m, 2H), 7.37 (m, 6H), 7.24 (d, J => 8.8 Hz, 2H), 7.0 (d, J = 8.8 Hz, 2H), 6.89 (d, J =8.2 Hz, 1H), 5.85 (br S, 245300 1H), 5.1 (s, 2H), 4.90 (t, J = 9.0 Hz, 1H), 3.69 (m, 1H), 1.40, 1.16 (s, 3H each); 13C NMR (DMS0-d6) 159.6, 156.3, 137.0, 132.6, 132.4, 128.5, 127.9, 127.7, 126.6, 125.0, 119.1, 117.8, 117.3, 115.2, 102.6, 80.4, 70.6, 69.4, 51.6, 26.6, 18.6; IR (KBr) 2978.0, 2936.0, 2226.3, 2180.7, 1610.0, 1581.3, 1510.9, 1489.7, 1267.5, 1238.5 cm"1.

Analysis calc'd for C27H2sNs03*0.34 H20: C, 68.47; H, 5.46; N, 14.79; Found: C, 68.55; H, 5.34; N, 14.71.

Example 41 trans-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-15 2, 2-dimethyl-2H-l-benzopyran-4-yl )-N' -(4-hydroxy-phenyl)quanidine To a solution of the title compound from Example 40 (0.7 g, 1.5 mmol) in ethanol (70 mL) 20 was added (10%) palladium on carbon (0.1 g). It was then treated with hydrogen in a balloon and heated at 60°C for 2 hours. The reaction was filtered through a pad of celite, the filtrate was washed with ethanol and concentrated in vacuo to 25 give the title compound as a colorless solid (0.5 g), m.p. 171-173°C: *H NMR (DMSO-ds) 6 9.40 (s, 1H), 9.03 (s, 1H), 7.58 (d, j = 8.2 Hz, 1H), 7.51 (s, 2H), 7.2 (s, 1H), 7.11 (d, J = 8.8 Hz,'2H), 6.89 (d, J = 8.2 Hz, 1H), 6.73 (d, J = 8.8 Hz, 2H), 30 5.85 (br s, 1H), 4.87 (t, J = 9.0 Hz, 1H), 3.71 (m, 1H), 1.38, 1.15 (s, 3H each); 13C NMR (DMSO-ds) 159.6, 156.3, 132.6, 132.4, 127.0, 126.6, 119.1, 117.8, 117.3, 115.6, .102.6, 80.4, 79.4, 70.6, 51.6, 2 4 5 3 0 0 26.7, 18.6; IR (KBr) 3485.6, 2986.0, 2941.6, 2226.0, 1585.6, 1514.2, 1491.1, 1307.8, 1271.2, 1128.4 cm"1.

Analysis calc'd for C2oHi9Ns03•0.4 H20: 5 C, 62.46; H, 5.19; N, 18.21; Found: C, 62.71; H, 5.17; N, 17.96.

Example 42 tra/is-N- (6-Acetyl-3,4-dihydro-3 -hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N"-cyano-N'-phenylquanidine The solution of N-cyano-N1-phenylthiourea 15 (0.98 g, 5.5 mmol, compound of Example 3, part A) and 6-acetyl-3,4-dihydro-2,2-dimethyl-3-hydroxy-4-amino-2H-l-benzopyran (1.0 g, 4.25 mmol, prepared according to Evans et al., J. Med. Chem♦, 1983, 26, 1582 and J. Med. Chem., 1986, 29, 2194) in 20 dimethylformamide (6 ml J under argon was treated with 1-(3-dimethylaminopropyl)-2-ethylcarbodiimide hydrochloride (1.1 g, 5.5 rnmol). The reaction was stirred at room temperature for 2 hours and then partitioned between 10% citric acid and ethyl 25 acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with water, sodium bicarbonate and brine. , After drying over anhydrous magnesium sulfate, the solvent was evaporated and the residue was 30 crystallized from ethyl acetate to yield the title compound (0.43 g), m.p. 182-184°C: *H NMR (DMS0-d6) 6 9.45 (s, 1H), 7.82 (m, 3H), 7.44 (s, 3H), 7.25 (s, 1H), 6.96 (d, J = 9.0 Hz, 1H), 6.0 (s, 1H), 5.1 (m, 1H), 4.15 (m, 1H), 3.8 (s, 1H), 2 4 5 3 0 2.61 (s, 3H), 1.52 (s, 3H), 1.29 (s, 3H); 13C NMR (CDC13) 6 196.2, 159.3, 156.6, 137.6, 129.7, 129.1, 128.4, 124.7, 123.5, 123.3, 117.2, 116.6, 80.0, 71.2, 52.3, 26.7, 26.3, 18.6; IR (KBr) 3412.3, 2978.3, 2935.8, 2179.7, 1670.5, 1602.9, 1577.9, 1493.0, 1359.9, 1271.2, 1126.5 cm"1.

Analysis calc'd for C21.H22N4O3-O.57 H20: C, 64.89; H, 6.00; N, 14.41; Found: C, 65.23; H, 6.11; N, 13.98.

Example 43 (3S-trans)-N-(3,4-Dichlorophenyl)-NH-cyano-N'-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-15 l-benzopyran-4-yl)quanidine A. N-Cyano-N'-(3,4-dichlorophenyl) thiourea The suspension of monosodiura cyanamide (1.6 g, 24.5 mmol) in absolute ethanol (50 mL) was 20 slowly treated with 3,4-dichlorophenylisothio-cyanate (5.0 g, 24.5 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 75°C for 4 hours. The reaction was cooled to room temperature and the colorless solid 25 was filtered and washed with ethanol to give the title A compound (5.0 g) as a colorless solid.

# B. (3S-trans)-N-(3,4-Dichlorophenyl)-N"-cyano-N*-(6-cyano-3,4-dihydro-3-hydroxy-2,2- dimethvl-2H-l-benzopyran-4-yl)quanidine The solution of the title A compound (1.47 g, 6.0 mmol) and (3S-trans )-4-amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbonitrile (1.0 g, 4.6 mmol, compound of Example 20, part B) 2 4 5 3 in dimethylformamide (10 mL) under argon was treated with 1-(3-dimethylaminopropyl)-2-ethyl-carbodiimide hydrochloride (1.13 g, 6:0 mmol). The reaction was stirred at room temperature for 2 5 hours and then partitioned between pH 4 buffer and ethyl acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts were washed with water (4 x 200 ml), sodium bicarbonate and brine. After drying over anhydrous magnesium 10 sulfate, the solvent was evaporated and the residue was purified by flash chromatography (ethyl acetate:hexanes/7:3) to yield a colorless solid (0.6 g). The solid was triturated with ethyl ether to give the title compound (0.5 g), 15 m.p. 168-170°C: JH NMR (CDC13) 6 9.30 (s, 1H), 7.64 (s, 1H), 7.58 (d, J = 2.4 Hz, 1H), 7.40 (m, 2H), 7.30 (dd, J = 2.3 •& 2.9, 1H), 6.85 (d, J = 8.8 Hz, 1H), 4.97 (m, 1H), 3.70 (d, J = 10.0 Hz, 1H), 1.49, 1.26 (s, 3H each); 13C NMR (CDCl3) 20 158.6, 155.8, 136.4, 131.9, 131.4, 129.7, 118.1> 117.3, 102.6, 79.6, 51.8, 25.8, 17.8; IR (KBr) 3398, 2980, 2225, 2183, 1610, 1581, 1489, 1371 cm"1. [aD]25 = -35.37° (c = 0.458, dimethylformamide ).

Analysis calc'd for C2ohi7C12N502•0.37 H20: C, 54.97; H, 4.09; N, 16.02; Cl, 16.22; Found: C, 55.39; H, 4.04; N, 15.60; Cl, 15.97. 245300 Example 44 (3S-trans )-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N' -5 [4-( trifluoromethvl )phenyl) 1 quanidine A. N-Cyano-N1 -(4-tri fluoromethylphenyl)- thiourea The suspension of monosodium cyanamide (0.63 g, 9.8 nmol) in absolute ethanol (50 mL) was slowly treated with 4-trifluoromethylphenyliso-thiocyanate (2.0 g, 9.8 mmol). The reaction was allowed to stir at room temperature for 1 hour and then heated at 7 5°C for 4 hours. The reaction was 15 cooled to room temperature and the colorless solid was filtered and washed with ethanol to give the title compound (2.0 g) as a colorless solid.

B. (3S-trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-20 3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4r yl)-N'-[4-(tn f luoromethy 1)phenvl)]quanidine The solution of the title A compound (1.3 g, 5.3 mmol) and (3S-trans)-4-aminc-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-6-carbo-25 nitrile (0.83 g, 3.8 mmol, prepared according to Example 20, part B) in dimethylformamide (10 mL; under argon was treated with 1-(3-dimethylaminopropyl )-2-ethylcarbodnmide hydrochloride (1.1 g, 5.7 mmol). The reaction was stirred at room 30 temperature for 2 hours and then partitioned between pH 4 buffer a'nd ethyl acetate. The aqueous phase was reextracted with ethyl acetate and the combined extracts ware washed with water (4 x 200 ml), sodium bicarbonate and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated and the resiude was purified by flash chromatography eluting with a mixture of ethyl acetate/hexanes (7:3). The solid was triturated with ethyl ether to give the title compound (0.45 g), m.p. 209-210°C: 1E NMR (CDC13) 6 9.41 (s, 1H), 7.60 (m, 6H), 6 85 (d, J = 8.8 Hz, 1H), 4.99 (m, 1H), 3.74 (d, J = 9.4 Hz, 1H), 1.50, 1.28 (s, 3H each); 13C NMR (CDCl3) 158.7, 156.0, 140.4, 132.1, 125.5, 123.9, 121.9, 118.3, 117.5, 102.8, 79.8, 52.1, 25.9, 18.0; IR (KBr) 3403, 2226, 2184, 1588, 1491, 1325, 1126, 1069 cm"1. foD]2S = -40.2 (c = 0.567, MeOH).

Analysis calc'd for C2iH!8F3Ns02: C, 58.74; H, 4.23; N, 16.31; F, 13.27; Found: C, 59.15; H, 4.16; N, 16.18; F, 13.53. 245300 Example 45 In this example, rat aorta and rat heart data are presented for the compounds of Examples 27, 28, 30, 31, 33-35, 37-41, 43 and 44. The methodologies are described immediately below. Briefly, the rat aorta data is compared to the potent vasodilator cromakalim to illustrate the selectivity (lack of vasodilating effect in normal tissue) of the present compounds. The rat heart methodology involves a globally ischemic rat' heart model which is believed to be a reliable indicator of protection for organ surgery procedures.' This is because the laboratory-induced isolation and ischemic event, including perfusion with a cardioplegic solution, reasonably duplicates the environment and conditions for the heart during bypass and transplant. Some compounds were tested by measuring the percent decrease in lactate dehydrogenase (LDH) release; others were tested by measuring the increase in time to contracture.

Rat Aorta Methodology Following sacrifice, • the thoracic aorta was removed from male Wistar Kyoto rats and placed in cold physiological salt solution (PSS) containing (in mM) : 118.4 NaCl, 4.7 KCl, 1.2 KH2P04, 1.2 MgS04, 2.5 CaCl2, 25.0 NaHCC>3 and 11.7 glucose.

Rings were cut from each aorta and the endothelium was mechanically removed. The rings were individually mounted-for isometric force recording and suspended in individual chambers containing PSS at 37°C aerated with 95% 02/5% CO2 (pH 7.4).

During the equilibration period, the rings were stretched to 2 g and stimulated with 24.7 mM KCl several times to determine contractility. 24 5 3 0 0 Following the equilibration period, propranolol (1 flM) was added to each chamber to block beta-adrenoceptors. Rings were contracted with 0.3 (iM methoxamine, then a cumulative concentration relaxation curve was obtained for the test compound. After the final bath concentration was attained, "reversal" of the relaxation was attempted (in the continued presence of the test compound) by addition of sufficient quantities of a 10 4m KCl solution to obtain a final bath concentration of 60 mM KCl.

Data are presented as mean +. SEM for at least 4 rings from different animals. The IC50 values were determined from a quadratic fit to the 15 logit transformation of the concentration relaxation curves. Concentrated stock solutions of test compounds were prepared daily in water or DMSO as appropriate.

Rat Heart (* decrease in LDH) Preparation of the Isolated Perfused Hearts.

Male Sprague-Dawley rats (450-550 g) were used in all experiments. The rats were anesthetized using 3 0 mg/kg sodium pentobarbital (i.p.). They were intuba*~d and then treated with i.v., heparin (1000 25 U/kg) . While being mechanically ventilated, their hearts were perfused in situ via retrograde cannulation of the aorta. The hearts were then excised and quickly moved to a Langendorff apparatus where they were perfused with Krebs-30 Henseleit bicarbonate buffer (112 mM NaCls, 25 mM NaHCC>3, 5 mM KCl, 1.2 mM MgS04, 1 mM KH2PO4, 1.25 mM CaCl2, 11.5 mM dextrose, and 2 mM pyruvate bubbled with 95% O2 - 5% CO2) at a constant pressure (75 mm Hg). A water filled latex balloon attached to a s Cm metal cannula was then inserted into the left ventricle and connected to a Statham pressure transducer for measurement of left ventricular pressure. The hearts were allowed to equilibrate 5 for 15 minutes at which time end diastolic pressure (EDP'z was adjusted to 5 mm Hg and this was maintained for 5 minutes. Pre-ischemia or pre-drug function, heart rate and coronary flow (extracorporeal electromagnetic flow probe, Carolina 10 Medical Electronics, King, N.C.) were then measured. Cardiac function was determined using the double product of heart rate (HR) x left ventricular developed pressure (LVDP) divided by 1000. Cardiac temperature was maintained 15 throughout the experiment by submerging the hearts in 37°C buffer which was allowed to accumulate in a stoppered, heated chamber.

Experimental Prot-.ocnl. Once the baseline measurements were taken, the hearts were treated 20 with the listed compounds or with vehicle buffer (0.01% DMSO, n = 7). All of these hearts were treated with their respective drugs or vehicle for ten minutes. At this time, post-drug cardiac function and flow were measured and then the hearts 25 were made globally ischemic by shutting off the buffer perfusion. The ischemia was maintained for 25 minutes, the hearts were then reperfused with nondrug treated buffer. Reperfusion was maintained for a total of 30 minutes and at this time 30 reperfusion function and flow were again determined. The results are summarized in the TABLE below. 4 2 4 5-3 0 Rat Heart Time to Contracture (EC^l Time to contracture; EC25; concentration increasing time to contracture by 25%; jan increase in time to contracture at 10 JIM.

Claims (13)

27 28 30 31 33 34 35 37 38 39 40 41 43 44 ui Rat Aorta (IC50, mM) or % relaxation H in H O ui TABLE Rat Heart % decrease in LDH at 10 pM (EC25 pM) Increase in time to contracture at 10 nM 1.85 34 1.6 1.1 2 1.8 1.4 1.4 0.7 0.7 4.3 2.2 0.5 8.1 2% 0% 13.6 mM 18.3 pM 8% 5. 6 nM 16 flM 3.8 fiM 3.5 ]M 1.4 pM 6% 12.9 mM 13.4 mM 0.032 9.0 MM 245 - 99 - WHAT^/WE CLAIM IS;

1. The use of an organ-protecting amount of a compound of the formula S=<Sp? wherein a, b, and c are all carbons or one of a, and c can be nitrogen or -NO- and the others are carbons; R? Rs Rs ^n/ r }/ Rx is \=NCN or Rjq" RsV ( - ^>=NCN; ^ N n I R2 is hydrogen, hydroxy or -0CCH3 & R3 and R« are each independently hydrogen, alkyl or arylalkyl, or, R3 and R« taken together with the carbon atom to which they are attached form a 5- to 7-membered carbocyclic ring; R5 is selected from H, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, arylalkyl, cycloalkylalkyl, -CN, -NO2, -COR, -COOR, -CONHR, -CONR2, -CF3, S-alkyl, -SOalkyl, -S02alkyl, -P(O-alkyl)2 , -P -4-R, °-^>n halogen, amino, substituted amino, O-alkyl, 0CF3, 0CH2CF3, -OCOalkyl, -OCONRalkyl, -NRCOalkyl and NRCOOalkyl, NRCONR2 wherein R in each of the abov groups can be hydrogen, alkyl, aryl, arylalkyl,, cycloalkyl, or (cycloalkyl)alkyl; 245 300 -100- R6 is selected from H, alkyl, OH, O-alkyl, amino, substituted amino, CN, and.?V02; R7 and Rg are each independently selected from hydrogen, alkyl, alkenyl, aryl, heterocyclo, 5 (heterocyclo)alkyl, arylalkyl, cycloalkyl and (cycloalkyl)alkyl, substituted alkyl wherein the substituents include alkoxy, alkylthio and substituted amino, or R7 and Rs taken together with the nitrogen atom to which they are attached 10 form 1-pyrrolidinyl, 1-piperidinyl, 1-azepinyl, 4-morpholinyl, 4-thiamorpholinyl, 1-piperazinyl, 4-alkyl-l-pipe.razinyl or 4-arylalkyl-l-piperazinyl, wherein each of the so-formed groups can be substituted with alkyl, alkoxy, alkylthio, halogen 15 or trifluoromethy1; Rg and R10 are selected from hydrogen, alkyl, alkenyl, aryl, arylalkyl, cycloalkyl or cycloalkylalkyl; and n is 1, 2 or 3, in the manufacture of a medicament for protecting an organ from ischemic, damage in a mammalian species subject to an organ surgery procedure. 24 5 3 0 0 101

2. The use ; of claim 1 wherein said procedure is cardiopulmonary bypass surgery.

3. The use of claim 1 wherein said procedure is organ transplant surgery. 10

4. The use ot claim 3 wherein said procedure is heart transplant surgery.

5. The use of claim 1 wherein said medicament is manufactured by adding said compound to a solution used to preserve, protect or maintain organ function. 15

6. The use of claim 5 wherein a cardiac-protecting amount of said compound is added to said solution, said solution being a cardioplegic solution used to arrest, perfuse, store and/or protect a heart involved in a cardio- 20 pulmonary bypass or heart transplant procedure.

7. The use of claim 1 wherein said medicament is formulated to be administered to a mammalian specie undergoing an organ surgery procedure before and/or during and/or after said procedure. 25

8. The use of claims 1 or 4 wherein said medicament is formulated to be administered to an organ donor before and/or during and/or after removal of said organ from said donor.

9. The use of claim 1 wherein R7 is substituted phenyl. i

10. The use of claim 9 wherein the substituents of the substituted phenyl are selected from one or more halogens, haloalkyl, cyano, nitro, alkoxy, or aryla'ikoxy.

11. The use of claim 1 wherein the compound is selected from: 245300 102 (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2 , 2-dimethyl-2H-l-benzopyran-4-yl) —N 1 — (4 — cyanophenyl)guanidine, (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2 ,2-dimethyl-2H-l-benzopyran-4-yl) -N ' - (4-methoxyphenyl)guanidine, N"-Cyano-N-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-l-benzopyran-4-yl)-N1-phenylguanidine, (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N1-(4-nitro-phenyl)guanidine, (trans)-N-(4-Chlorophenyl)-N"-cyano-N-(6-cyano-3,4-dihy ro-3-hydroxy-2,2-dimethyl-2H-l-benzo-pyran-4-yl)guanidine, (trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N1-(2-pyridinylmethyl) guanidine, (trans)-N-(2-Chlorophenyl)-N"-cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzo-pyran-4-yl) guanidine, • (trans)-N-(3-Chlorophenyl)-N"-cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzo-pyran-4-yl)guanidine, (trans)-N-(4-Fluorophenyl)-N"-cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzo-pyran-4-yl)guanidine, 103 245300 (trans)-N"-cyano-N-[3-(Acetyloxy)-6-cyano-3,4-dihydro-2,2-dimethyl-2H-l-benzopyran-4yl]-N'-phenylguanidine, • (3S-trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-(4-fluoropheny1)guanidine, (3S-trans)-N-(4-Chlorophenyl)-N"-cyano-N' - (6-cyano-3,4-dihydro-3-rhydroxy-2,2-dimethyl-2H- 1-benzopyran-4-yl)guanidine, (3S-trans) -N- (3-Chlorophenyl) -N'.'-cyano-N ' -(6 cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-ben z opyran-4-y1)guanidine, trans-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-[4-(phenyl-methoxy)phenyl)guanidine, trans-N"-Cyano-N-{6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-(4-hydroxy-phenyl)guanidine, trans-N-(6-Acetyl-3,4-dih/dro-3-hydroxy-2, 2-dimethyl-2H-l-benzopyran-4-yl)-N"-cyano-N'-phenylguanidine, l-benzopyran-4-yl)guanidine, and (3S-trans)-N"-Cyano-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-l-benzopyran-4-yl)-N'-[4-{trifluoromethy1)phenyl)]guanidine.

12. The use of a compound as defined in claim 1 in the manufacture of a medicament substantially herein described with reference to example 45 in, ^ (3S-trang).-N- (3,4-Dichlorophenyl) -N "-cyano-N1-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H- herein. •W? £ C -104- 245300

13. A cardioplegic solution comprising a cardiac protecting amount of a compound of the formula wherein a, b, and c are all carbons or one of a, b and c can be nitrogen or -NO- and the others are carbons; \ /' nn/ Ra is \=NCN or R{o R9V ( 'n Ra =NCN; N R2 is hydrogen, hydroxy or -OCCH3 I R3 and R4 are each independently hydrogen, alkyl or arylalkyl, or, R3 and R4 taken together with the carbon atom to which they are attached form a 5- to 7-membered carbocyclic ring; Rs is selected from H, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, arylalkyl, cycloalkylalkyl, -CN, -N02, -COR, -COOR, -CONHR, -CONR2/ -CF3, S-alkyl, -SOalkyl, -S02alkyl, if f?/°n -P (O-alkyl)2, -p' R, o-f-J) >v t'N T n ; J \ i- \ rs halogen, amino, substituted amino, O-alkyl, 0CF3, OCH2CF3, -OCOalkyl, -OCONRalkyl, -NRCOalkyl and NRCOOalkyl, NRC0NR2 wherein R in each of the above groups can be hydrogen, alkyl, aryl, arylalkyl cycloalkyl, or (cycloalkyl)alkyl; c E *;24 5 3 0 0;-105-;R6 is selected from H, alkyl, OH, O-alkyl, amino, substituted amino, CN, and N02;;R7 and Rg are each independently selected from hydrogen, alkyl, alkenyl, aryl, heterocyclo, (heterocyclo)alkyl, arylalkyl, cycloalkyl and (cycloalkyl)alkyl, substituted alkyl wherein the substituents include alkoxy, alkylthio and substituted amino, or R7 and Ra taken together with the nitrogen atom to which they are attached form 1-pyrrolidinyl, 1-piperidinyl, 1-azepinyl, 4-morpholinyl, 4-thiamorpholinyl, 1-piperazinyl, 4-alkyl-l-piperazinyl or 4-arylalkyl-l-piperazinyl, wherein each of the so-formed groups can be substituted with alkyl, alkoxy, alkylthio, halogen or trifluoromethyl;;R9 and R10 are selected from hydrogen,;alkyl, alkenyl, aryl, arylalkyl, cycloalkyl or cycloalkylalkyl; and n is 1, 2 or 3 ,;and a suitable carrier therefor.;&y>tis/their authorised Agent*., A. J. PARK & SON, Per ^ END OF CLAIMS