IE841345L - Fused tricyclic derivatives of naphthyridines and related¹heterocyclics - Google Patents

Description

PATENTS ACT 1964 COMPLETE SPECIFICATION "FUSED TRICYCLIC DERIVATIVES OF NAPHTHYRIDINONE, PYRIDONE AND QUINOLONE AND THE CORRESPONDING THIONES" APt-UCAr?QN <7- -1 SCHERING CORPORATION, a Corporation organised and existing under the laws of the State of New Jersey, United States of America, of 2000 Galloping Hill Road, Kenilworth, New Jersey 07033, United States of America.

"FUSED TRICYCLIC DERIVATIVES OF NAPHTHYRIDINONE, PYRIDONE AND QUINOLONE AND THE CORRESPONDING THIONES" The present invention relates to novel tricyclic compounds which possess anti-allergic, antiinflammatory and cytoprotective activity. pyrano-5*,6* :3,4-(2-oxo-1,2-dihydroquinoline) and its N-phenyl derivative is described in Bull. Soc. Chim. Fr., pp. 364-9 (1968) (C.A. 68:114419c).

The invention sought to be patented in its chemical compound aspect is a compound having the structural formula I The preparation of the compound 2,-methyl- w 2- whereirn: A is or c*B A' b is independently oxygen or sulfur; -R® may be the same or different and are hydrogen or alkyl having from 1 to 6 carbon atoms or two adjacent R1-R® substituents may be combined to form an additional 10 carbon to carbon bond; 1 and m may be the same or different and are 0 or 1; the ring labeled, Q, may optionally contain up to two additional double bonds; 15 n is 0, 1 or 2; W and X may be the same or different and are hydrogen, hydroxy, alkyl having from 1 to 6 carbon atoms, halogen, nitro, alkoxy having from 1 to 6 carbon atoms, tri-fluoromethyl, cyano, cycloalkyl having from 3 to 7 carbon atoms, alkenyloxy having from 3 to 6 carbon atoms, alkynyloxy having from 3 to 6 carbon atoms, S(0)p-Ra [wherein p is 0, 1 or 2 and Ra is alkyl having from 1 to 6 carbon atoms], NHS02Ra [wherein Ra is defined herein], NHSO^F-j, NHCOCF3, S02NH2f CORb[wherein Rb is OH, NH2 or OR® (wherein Ra is defined herein)] , O-D-COR*5 [wherein D is alkylene having from 1 to 4 carbon 5 atoms and Rb is defined herein], or NHCORc [wherein Rc is hydrogen, alkyl having from 1 to 6 carbon atoms, alkoxy having from 1 to 6 carbon atoms, CORd (wherein Rd is hydroxy or alkoxy having from 1 to 6 carbon atoms) or NHRe 10 (wherein Re is hydrogen or alkyl having from 1 to 6 carbon atoms)], or phenoxy [wherein the benzene ring may be substituted with any of the other substituents W and X]; Y and Z may be the same or different and are CH or N; V is phenyl, naphthyl, indenyl, indanyl, pyridyl, pyrimidinyl, thienyl, furyl or thiazolyl, any of which may be substituted 20 with W and X as defined herein; and R^ and R^® «r«* independently hydrogen or alkyl having from 1 to 6 carbon atoms.

A preferred subgenus of compounds is that wherein B is oxygen.

A more preferred subgenus of compounds is that wherein B is oxygen and A is A'. -3a)- Compounds of interest include those where n is zero, particularly those wherein also Y is CH, for instance those of the formula Q in which l,m,B,V,W,X, Z and R'-R° are as defined above.

Compounds of formula I"1 which are of interest include those where Z is N; particularly where both 1 and m are zero or where both 1 and m are 1, especially such compounds in which B is oxygen and where V may be -3 b)- Thus a particularly preferred sub-genus of compounds is that having the structural formula w x of which of interest are those having the formula X* and x" and especially those of formula X' and X" in which R'-R® are hydrogen and or methyl, for instance where none or one of R'-R® is methyl and the rest are hydrogen. -3 c)- Another sub-genus of interest is that of the structural formula XI in particular of the structural formula Of Interest are compounds of formula XI1 (and also of formulae X' and X"in which none or one of R'-R® is methyl and the rest are hydrogen) wherein W is 3-chloro and X is halogen, chlorine or fluorine*, those in which W is 3-raethQxy and X is hydrogen or fluorine; and also those in which W and X are both hydrogen.

Preferred species are those having the names: 3,5-dihydro-5-phenyl-furo[3,2-c][1,8]naphthyridin-4[2H]« one; 6-phenyl-2,3,4,6-tetrahydro-pyrano[3,2-c][1,8]-naphthyridin-5-one; 2-methyl-3,5-dihydro-5-phenyl-furo[3,2-c][1,8]-naphthyridin-4[2Hj-one; 3,9-dihydro-9-phenyl-furo[2,3-b]11,8]naphthyridin-412H3 • one; 3,9-dihydro-9-(p-methylphenyl)-furo[2,3-b][1,8]naphthy-ridin-4[2H]-one; 3,9-dihydro-2-methyl-9-phenyl-furo[2,3-b][1,8]naphthyridin-4 [2 The invention sought to be patented in a first pharmaceutical method aspect is a method for treating 5 allergic reactions in a mammal which comprises administering an anti-allergic effective amount of the above-defined pharmaceutical composition to said mammal.

The invention sought to be patented in a second pharmaceutical method aspect is a method for treating 10 inflammation in a mammal which comprises administering an anti-inflammatory effective amount of the above-defined pharmaceutical composition to said mammal.

The invention sought to be patented in a third pharmaceutical method aspect is a method for treating 15 peptic ulcers in a mammal which comprises administering a cytoprotective effective amount of the above defined pharmaceutical composition to said mammal.

The compounds of the invention may be prepared from a properly substituted 3-(hydroxyalkyl)-4-hydroxy-1-20 substituted-[quinolin; 1,5-naphthyridin; or 1,8- naphthyridinl-2 (1j0-one, a 7-(hydroxyalkyl)-8-hydroxy-5-substituted-pyrido[2,3-b]pyrazin-6(5HJ-one having the structural formula II OH II wherein B, V, W, X, Y, Z, R*-R^®, 1, m and n are as defined herein.

Compounds of the invention wherein A is A', and m is 0 i.e., compounds having structural formula I' may be prepared by treating a correspondingly substituted compound having structural formula II with a strong aqueous acid solution. Useful acids are sulfuric acid, hydrobromic acid, perchloric acid, trifluoroacetic acid, phosphoric acid and the like. A compatible non-reactive solvent may be utilized to aid solubility, if desired. The use of approximately 30% sulfuric acid without additional solvent is preferred.

In this procedure, the starting compound II is dissolved or suspended in the reaction medium and heated to reflux temperature over a period of about 1 hour. The mixture is maintained at reflux temperature until the reaction is substantially complete. The progress of the reaction may be monitored by standard means, for example thin layer chromatographic means, and is usually substantially completed after about 6 hours. The product may be recovered, for example, by adding the reaction mixture to an excess of cold dilute base solution such as sodium hydroxide, potassium carbonate or the like and isolating the product by standard means such as extraction with an organic solvent or by filtration. Further purification, if desired, may be effected by recrystallization.

The thiated derivatives of I1 may be prepared by procedures described below.

Compounds of the invention wherein A is A", i.e., compounds having structural formula I'' I" may be prepared by treating a corresponding substituted compound having structural formula II with a dehydrating reagent under anhydrous conditions. Suitable dehydrating reagents for this purpose are phosphorus pentoxide/methanesulfonic acid [known as Eaton's reagent, J. Org. Chem., 35, 4071 (1973)] and thionyl chloride/pyridine/ methylene chloride, for example.

In the preferred method for preparing compounds having structural formula I'1, a correspondingly substituted compound having structural formula II is - dissolved or suspended in Eaton's seagent at elevated temperature until the reaction is substantially complete. Temperatures from about 50* to 100*C are useful. At temperatures of from about 60* to 80*C, the reaction has been observed to be substantially completed in about 1 to about 4 hours. by standard means. The product may be recovered, for example, by adding the reaction mixture to an excess of cold dilute base solution such as sodium hydroxide, potassium carbonate or the like and isolating the product by standard means such as extraction with an organic solvent or by filtration. Further purification, if desired, may be effected by recrystallization.

The thiated derivatives of I" may be prepared by procedures described below.

Compounds of the invention wherein A is A* and 1 and m are both 1, i.e. compounds having the structural formula I'a The progress of the reaction may be monitored X (CR9R10) -V n 11 a may be prepared by the cyclization of a compound having structural formula IIA rvcrvi cr5r6] cr7r8]m-0s02ch3 (cr9r10)n-v IIA This cyclization is preferably carried out by treating IIA with a base such as cesium carbonate in a convenient solvent such as N,N-dimethylformamide. The product may be isolated and purified by standard methods.

Other bas^/solvent pairs m&y be utilised for this cyclization such as sodium or potassium carbonate in N,N-dimethylformamide or N,N-dimethyl acetamide; potassium carbonate in acetone; tetra-jv-butylammonium hydroxide, triethylamine or 1,8-diazabicyclo[5.4.0]undec-7-ene in methylene chloride or chloroform. In addition, the methanesulfonate leaving group of IIA may be replaced by other leaving groups known in the art such as bromine, chlorine and other sulfonic acid esters derived from acids such as benzenesulfonic acid, j>-toluenesulfonic acid and £-bromobenzenesulfonic acid.

The compounds having structural formula II may be prepared by known methods from known starting materials. Exemplary of such starting materials are 2- anilinonicotinic acids prepared, for example, as described in United States Reissue Patent 26,655, and 2-phenylamino-3-pyrazine carboxylate esters which may be prepared substantially as exemplified herein starting 5 with a 2-amino-3-pyrazine carboxylate ester. 2-Anilino- 3-pyrazine carboxylic acid is a known compound, C.A., 75, 20154e (1971), which may be esterified by standard procedures.

The compounds having structural formula IIA may 10 be prepared from the corresponding substituted compound having structural formula II by known methods. Por example, compound II may be treated with methanesulfonic acid in the presence of a dehydrating agent such as phosphorus pentoxide (Eaton's reagent).

The compounds having structural formula I' may also be produced from a correspondingly substituted compound having structural formula I". Thus for example, a compound having structural formula I" may be treated with a nucleophile such as bromide or iodide anion under 20 anhydrous conditions in a non-reactive solvent such as Nyll-dimethylacetainide between about 60*C and the mixture'u reflux temperature for about 2 to about 12 hours to effect this conversion.

Certain compounds of the invention having 25 structural formula I in which one or both of B are sulfur may be prepared from the correspondingly substituted compound having structural formula II by treatment with, for example, Lawesson's Reagent (2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide] in hot 30 toluene. Under these conditions both cyclization of II and thiation are found to occur. Also, reaction of Lawesson's Reagent with compounds I' yields mainly a singly thiated product, i.e. the product in which the carbonyl oxygen atom has been replaced by sulfur (a 35 thioamide); whereas -O- is not replaced.

In addition, certain coapounds wherein one of the B substituents is oxygen and one is sulfur may be rearranged by treatment with a nucleophile as described above. Thus, for example, a thioamide compound wherein 5 the cyclic B atom is oxygen having structural formula I', may be rearranged to produce a coapound having structural formula I" wherein the cyclic B atom is sulfur and the doubly bonded B atom is oxygen.

The above-described thiation conversions and 10 rearrangements are further described below by use of diagrams. Por reasons of convenience and clarity, abbreviated structures are utilized in the diagrams. The references noted on the arrows refer to the procedures of the indicated working examples.

OH Examples 1 and 2 XT" I A* Example 15 Example 16 A? Example 13 Xjd Example 12 When utilized herein and in the appended claims the b*low listed terms, unless specified otherwise, are defined as follows: halogen - fluorine, chlorine, bromine and 5 iodine; alkyl and alkoxy - comprised of straight and branched carbon chains containing from 1 to 6 carbon atoms; alkenyloxy - comprised of straight and branched 10 carbon chains containing from 3 to 8 carbon atoms and comprising a carbon to carbon double bond; and alkynyloxy - comprised of straight and branched carbon chains containing from 3 to 8 carbon -J5 atoms and comprising a carbon to carbon triple bond.

The compounds of the invention may possibly contain two different "B" substituents. It is intended that both may simultaneously be oxygen or sulfur, or that 2o either may be oxygen or sulfur.

In certain compounds of the invention, the ring labeled C, m*y contain up to two additional double bonds which double bonds ace formed by the combination of two 1 ft adjacent substituents, R'-R . Thus, for example, when Q 25 is a 7 membered ring (1 and m are both equal to 1) it may contain 3 double bonds. When multiple double bonds are present, they will be non-cumulated double bonds.

The compounds of the invention are comprised of a -(CR9R10)n- substituent wherein the R9 and R10 groups 30 may vary independently. Thus, for example, when n equals 2 the following patterns of substitution (wherein hydrogen and CH3 are used to represent any substituent, R9 or R10,) are contemplated: -C(CH3)2CH2-, -CH2C(CH3)2-, -CH2CH(CH3)-, -CH(CH3)CH2-, -(C(CH3)H)2- and the 35 like. In addition when n equals 2, substituents such as -C(CH3)2CH(C2H5)-, -CH(CH3)CH(C2H5)-, -CH(_i_-C3H7)CH(C2H5)- are also contemplated.

Certain compounds of the invention may exist in isomeric forms. The invention contemplates all such 5 isomers both in pure form and in admixture, including racemic mixtures.

The compounds of this invention can be used to treat allergy caused diseases and their preferred use is for treating allergic chronic obstructive lung 10 diseases. Chronic obstructive lung disease as used herein means disease conditions in which the passage of air through the lungs is obstructed or diminished such as is the case in asthma, bronchitis and the like.

The anti-allergy method of this invention is 15 identified by tests which measure a compound's inhibition of anaphylactic bronchospasm in sensitized guinea pigs having antigen induced bronchoconstriction. For example, the compound 3,5-dihydro-5-phenylfuro[3,2-c)11,8] naphthyridin-4[2H]-one was found to inhibit anaphylactic 20 bronchospasms in such test procedure when given at an oral dose of 3-5 mg/kg. Said compound was also found to inhibit allergen-induced histamine release from guinea pig and human sensitized tissue. The compounds are effective non-adrenergic, non-anticholinergic 25 antianaphylactic agents. When administered orally they are active at doses from about 0.1 to 10 mg/kg of body weight; when administered parenterally, e.g., intravenously, the compounds are active at dosages of from about 0.05 to 5 mg/kg body weight; when administered 30 by inhalation (aerosol or nebulizer) the compounds are active at dosages of about Q.2§ to 5 mg per puff, one to four puffs may be taken every 4 hours.

The compounds of this invention are also useful for the treatment of inflammation. The anti-inflammatory 35 use of the compounds of the present invention may be demonstrated by the Reversed Passive Arthus Reaction (RPAR) Synovitis technique as set forth below using male Lewis rats (obtained from Charles River Breeding Laboratories) weighing 200-250 grams. The potency of the 5 compounds is determined using indomethacin as the standard. On the basis of the test results, an oral dosage range of about 5 milligrams per kilogram of body weight per day to about 50 milligrams per kilogram of body weight per day in divided doses taken at about 4 10 hour intervals is recommended.

The dosage to be administered and the route of administration depends upon the particular compound used, the age and general health of the patient and the severity of the inflammatory condition. Thus, the dose 15 ultimately decided upon must be left to the judgment of a trained health-care practitioner.

RPAR Synovitis Technique A Lewis rat is dosed orally with drug or placebo one hour prior to intravenous administration of 20 2.28 mg of bovine serum albumin (BSA) in 0.2 cc of pyrogen-free saline followed by the irtw.art? cular injection of 0.54 mg of rabbit anti-BSA antibody in 0.03 cc of pyrogen-free saline into one knee joint. The contralateral knee is injected with 0.03 cc of pyrogen 25 free saline. All injections are made with the animal under light ether anesthesia. Three hours later the rat is again dosed orally with drug or placebo. All drug doses are split. That is, one-half of the dose is administered before lesion induction and one-half is 30 administered after lesion induction.

The following morning (about 17 hours after lesion induction) the rat is killed and both knee joints are exposed. The subpatellar areolar tissue with attendant synovium is excised and weighed. Differences between the weight of antibody and saline injected knees are considered to represent the inflammatory response for each* animal (delta synovial weight). Differences in delta synovial weight between lesion controls and drug-5 treated rats are evaluated for statistical significance with an analysis of variance. Relative potencies are determined with a linear regression analysis.

The compounds of this invention are also useful in the treatment of peptic ulcers. They display chemo-10 therapeutic activity which enables them to relieve the symptoms of peptic ulcer disease, stress ulceration, and promote healing of gastric and/or duodenal ulcers. The antiulcer activity of the compounds of this invention is identified by tests which measure the cytoprotective 15 effect in rats. The compounds are also useful as conjunctive therapeutic agents for coadministration with such antiinflammatory/analgesic agents as aspirin, indomethacin, phenylbutazone, ibuprofen, naproxen, tolmetin and other agents. The compounds of this 20 invention prevent the untoward side effects of irritation and damage to the gastrointestinal tract caused by such agents.

The compounds of this invention are evaluated for their antiulcer activity characteristics by standard 25 biological testing procedures.

In cytoprotective tests in- rats in which ethanol is employed to induce gastrointestinal damage, the compounds of this invention are found to be effective at doses of about 0.05-50 mg/kg of body weight per day. 30 Preferably the total dosages are administered in 2-4 divided doses per day.

When administered parenterally, e.g. intravenously, the compounds are administered at a dosage range of about 0.01-10 mg/kg of body weight in single or .35 multiple daily doses.

To treat peptic ulcer disease, and prevent and treat drug-induced gastric ulceration, the active com-pounds of this invention can be administered in unit dosage forms such as tablets, capsules, pills, powders, 5 granules, sterile parenteral solutions or suspensions, suppositories, mechanical delivery devices, e.g. transdermal, and the like.

The compounds of the invention of formula I can exist in unsolvated as well as solvated forms, including 10 hydrated forms. In general, the solvated forms, with pharmaceutical^ acceptable solvents such as water, ethanol and the like are equivalent to the unsolvated forms for purposes of the invention.

For preparing pharmaceutical compositions from 15 the compounds described by this invention, inert, pharmaceutical^ acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, dispersible granules, capsules, cachets and suppositories. A solid carrier can be one or more 20 substances which may also act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders or tablet disintegrating agents; it can also be an encapsulating material. In powders, the carrier is a finely divided solid which is in admixture with the 25 finely divided active compound. In the tablet the active compound is mixed with carrier having the necessary binding properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain from 5 or 10 to about 70 percent of 30 the active ingredient. Suitable solid carriers are magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, a low melting wax, cocoa butter and the like. The term "pre-35 paration" is intended to include the formulation of the active compound with encapsulating material as carrier providing a capsule in which the active component (with or %/ithout other carriers) is surrounded by carrier, which is thus in association with it. Similarly, cachets 5 are included. Tablets, powders, cachets and capsules can be used as solid dosage forms suitable for oral administration.

For preparing suppositories, a low melting wax such as a mixture of fatty acid glycerides or cocoa 10 butter is first melted, and the active ingredient is dispersed homogeneously therein as by stirring. The molten homogeneous mixture is then poured into convenient sized molds, allowed to cool and thereby solidify.

Liquid form preparations include solutions, 15 suspensions and emulsions. As an example may be mentioned water or water-propylene glycol solutions for parenteral injection. Liquid preparations can also be formulated in solution in aqueous polyethylene glycol solution. Aqueous solutions suitable for oral use can be 20 prepared by adding the active component in water and adding suitable colorants, flavors, stabilizing, sweetening, solubilizing and thickening agents as desired. Aqueous suspensions suitable for oral use can be made by dispersing the finely divided active component 25 in water with viscous material, i.e., natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose and other well-known suspending agents.

Also included are solid form preparations which 30 are intended to be converted, shortly before use, to liquid form preparations for either oral or parenteral administration. Such liquid forms include solutions, suspensions and emulsions. These particular solid form preparations are most conveniently provided in unit dose -v.35 form and as such are used to provide a single liquid dosage unit. Alternately, sufficient solid may be provided so that after conversion to liquid form, multiple individual liquid doses may be obtained by measuring predetermined volumes of the liquid form 5 preparation as with a syringe, teaspoon or other volumetric container. When multiple liquid doses are so prepared, it is preferred to maintain the unused portion of said liquid doses at low temperature (i.e., under refrigeration) in order to retard possible 1Q decomposition. The solid form preparations intended to be converted to liquid form may contain, in addition to the active material, flavorants, colorants, stabilizers, buffers, artificial and natural sweeteners, dispersants, thickeners, solubilizing agents and the like. The 15 solvent utilized for preparing the liquid form preparation may be water, isotonic water, ethanol, glycerine, propylene glycol and the like as well as mixtures thereof. Naturally, the solvent utilized will be chosen with regard to the route of administration, for 20 example, liquid preparations containing large amounts of ethanol are not suitable for parenteral use.

Preferably, the pharmaceutical preparation is in unit dosage form. In such form, the preparation is subdivided into unit doses containing appropriate 25 quantities of the active component. The unit dosage form can be a packaged preparation, the package containing discrete quantities of preparation, for example, packeted tablets, capsules and powders in vials or ampoules. The unit dosage form can also be a capsule, cachet or tablet 30 itself or it can be the appropriate number of any of these in packaged form.

The quantity of active compound in a unit dose of preparation may be varied or adjusted from 1 mg to 100 mg according to the particular application and the 35 potency of the active ingredient. The compositions can, if desired, also contain other therapeutic agents.

The dosages may be varied depending upon the requirements of the patient, the severity of the con-ditibn being treated and the particular compound being employed. Determination of the proper dosage for a 5 particular situation is within the skill of the art.

Generally, treatment is initiated with smaller dosages which are less than the optimum dose of the compound. Thereafter, the dosage is increased by small increments until the optimum effect under the circumstances is 10 reached. Por convenience, the total daily dosage may be divided and administered in portions during the day if desired.

EXAMPLES EXAMPLE 1 3,9-Dihydro-9-(4-methylphenyl)-furo[2,3-b][1,8]- naphthyridin-4(2H)-one A solution of 4-hydroxy-3-(2-hydroxyethyl)-1-(4-methylphenyl)-1,8-naphthyridin-2( 1H_)-one (2.2 g.) in Eaton's Reagent (10% P2O5 in methane sulfonic acid; 40 20 ml.) was stirred in an atmosphere of nitrogen and heated to 70"C for 2 hr. After cooling, the product was poured into water, adjusted to pH 4 with NaHC03, filtered, washed with water, air dried and was recrystallized from isopropanol with decolorization to yield the product, 25 m.p. 246—248.5*C.

EXAMPLE 2 4>-»( 3 ,4-Dichlorophenyl)-3,9-dihydro-2-methyl-furo-[2,3-b][1,8]naphthyridin-4(2H)-one A solution of 1-(3,4-dichlorophenyl)^-hydroxys'2-hydroxypropyl)-1 ,8-naphthyridin-2( 1H_)-one (5 g.) in Eaton's Reagent (10% *n ®®thanesulfonic acid; 100 ml.), under an atmosphere of nitrogen, was heated at 70*C for 2 hr. The mixture was cooled and poured into water. The pH was adjusted to 7 with NaHCC^. The product was filtered off, washed with water, dried in air, and recrystaliized from isopropanol/charcoal to yield the product, m.p. 218-220.5*C.

The following compounds may be similarly prepared by substituting the appropriate starting material and using the method of Example 1 or 2. 3,9-Dihydro-9-phenyl-furo[2,3-b][1,8]-naphthyridin-4(2H)-one, m.p. 245-247'C 3,9-Dihydro-2-methyl-9-phenyl-furo[2,3-b][1,8]-naphthyridin-4(2j^-one, m.p. 207-209#C 3,9-Dihydro-2-(n-butyl)-9-phenyl-furo[2,3-b]-[1,8] naphthyridin-4(2_H)-one, m.p. 169-170"C 3,9-Dihydro-9-(4-fluorophenyl)-fuuo[2,3-b]-[1,8] naphthyridin-4(2JH)-one, m.p. 244-246#C 3,9-Dihydro-2-methyl-9-(4-f1uorophenyl)-furo-[2,3-b] [1,8] naphthyridin-4(2H_)-one, m.p. 195-197.5*C 3,9-Dihydro-2-(n-butyl)-9-(4-fluorophenyl)furo-[2,3-b] [1,8] naphthyridin-4(2jO-one 3,9-Dihydro-9-(4-chlorophenyl)-furo [2,3-b][1,8]-naphthyridin-4(2HJ-one, m.p. 243-245#C 3,9-Dihydro-2-methyl-9-(4-chlorophenyl)-furo-[2,3-b] [1,8] naphthyridin-4(2H_)-one 3,9-Dihydro-9-(4-methoxyphenyl)-furo[2,3-b]-[1,8] naphthyridin-4(2H_)-one, m.p. 227-228#C 3,9-Dihydro-2-methyl-9-(4-methoxyphenyl)-furo-[2,3-b] [1 #8] naphthyridin-4(2jO-one 3,9-Dihydro-9-(3-methoxyphenyl)-furo[2,3-b]-[1 ,8] naphthyridin-4 (2J[)-one 5 3,9-Dihydro-2-methyl-9-(3-methoxyphenyl)-furo- [2,3-b] [1 r8] naphthyridin-4(2H_)-one, m.p. 194-196#C 3,9-Dihydro-9-(3-methylmercaptophenyl)-furo-[2,3-b] 11,8] naphthyridin-4 (2H_)-one 3,9-Dihydro-2-methyl-9-(3-methylmercapto-10 phenyl)-furo[2,3-b] [1,8] naphthyridin-4(2H_)-one 3,9-Dihydro-9-benzyl-furo[2,3-b][1,8]-naphthyridin-4(2E)-one 3,9-Dihydro-2-methyl-9-benzyl-furo[2,3-b][1,8]-naphthyridin-4 (2H_)-one 3,9-Dihydro-9-(2-phenylethyl)-furo[2,3-b][1,8]-naphthyr idin-4 (2jO-one 3,9-Dihydro-2-methyl-9-(2-phenylethyl)-furo-[2,3-b] [1,8] naphthyridin-4 (2H_)-one 3,9-Dihydro-9-(2-thienylmethyl)-furo[2,3-b]-20 [1,8] naphthyridin-4(2H_)-one 3,9-Dihydro-9-(2-thiazolyl)-furo[2,3-b][1,8]-naphthyridin-4 (2ji) -one 3,9-Dihydro-9-(2-pyridyl)-furo[2,3-b][1,8]-naph t hy r i d i n- 4 (2H_) -one 25 3,9-Dihydro-9-[2-(2-pyridyl)ethyl]-furo[2,3-b]- [1,8] naphthyridin-4(2JH_)-one 3,9-Dihydro-9-(3-chlorophenyl)-furo [2,3-b] [1,8]-naphthyridin-4(2E)-one, m.p. >260*C 3,9-Dihydro-9-(3,5-dichloropheny1)-furo[2,3-b] 3Q [1,8] naphthyridin-4 (2j[)-one, m.p. 279-281 #C (dec.) 3,9-Dihydro-2-methyl-9-(3,5-dichloropheny1)-furo[2,3-b][1,8]naphthyridin-4(2HJ-one, m.p. 230-233*C 3,9-Dihydro-9-(2,3-dichlorophenyl)-furo[2,3-b] [1,8]naphthyridin-4(2H)-one 3 ,9-Dihydro-2-methyl-9-(2,3-dichlorophenyl)-furol2k,3-b] [1 ,8] naphthyridin-4 (2H_)-one 3,9-Dihydro-9-(2,5-dichlorophenyl)-furol2,3-b] [1,8] naphthyridin-4 (2JJ)-one 5 3,9-Dihydro-9-(3-chloro-4-fluorophenyl)-furo- [2,3-b] [1,8] naphthyridin-4(2JB)-one 3,9-Dihydro-2-methyl-9-(3-chloro-4-fluorophenyl )-f uro [2, 3-b] [1,8] naphthyridin-4 (2H_)-one 3,9-Dihydro-9-(3-trifluoromethylphenyl)-furo-10 [2,3-b] [1,8] naphthyridin-4(2_H)-one 3,9-Dihydro-2-methyl-9-(3-trifluoromethylphenyl )-f uro [2 ,3-b] [1,8] naphthyridin-4(2j|_)-one 3 ,9-Dihydro-9-(3,4-dichlorophenyl)-furo[2,3-b] [ 1,8] naphthyridin-4(2H_)-one, m.p. >260*C 15 3,9-Dihydro-2-methy1-9-(3-methylsulfonylami no- phenyl)-furo[2,3-b] [1,8] naphthyridin-4(2JB)-one, m.p. >260"C 3,9-Dihydro-2-methyl-9-(4-fluorophenyl)-furo-[2,3-b] quinolin-4 (2j!)-one 3,9-Dihydro-2-(n-butyl)-9-(4-fluorophenyl)furo' [2,3-b] quinolin-4 (2J3J-one qui nolin-4 (2H_)-one 3 ,9-Dihydro-2-methyl-9-(4-chlorophenyl)-furo-[2,3-b] quinolin-4 (2j0-one 3,9-Dihydro-9-(4-chlorophenyl)-furo[2,3-b]- 3,9-Dihydro-9-(3-methoxyphenyl)-furo[2,3-b]-qu i no! i n-4 (2H_) -one 3,9-Dihydro-2-methyl-9i-( 3-methoxyphenyl )-furo-[2,3-b] quinolin-4 (2H_)-one 5 3,9-Dihydro-9-(3-methylmercaptophenyl)-furo- [2,3-b] quinolin-4 (2J|) -one 3,9-Dihydro-2-methyl-9-(3-methylmercapto-phenyl)-furo[2,3-b]qui nolin-4(2jO -one 3 ,9-Dihydro-9-benzyl-furo[2,3-b] quinolin-4 (2J0- 1 o one 3,9-Dihydro-2-methyl-9-benzyl-furo[2,3-b]-qui noli n-4 (21!)-one 3,9-Dihydro-9-(2-phenylethyl)-furo[2,3-b]-qui noli n-4(2H)-one 15 3,9-Dihydro-2-methyl-9-(2-phenylethyl)-furo- [ 2,3-b] quinolin-4 (2H_) -one 3,9-Dihydro-9-(2-thienylmethyl)-furo[2,3-b]-quinolin-4 (2jU -one 3,9-Dihydro-9-(2-thiazolyl)-furo[2,3-b]-20 quinolin-4 (2J_)-one 3,9-Dihydro-9-(2-pyridyl)-furo[2,3-b]quinolin- 4 (2J_) -one 3,9-Dihydro-9-[2-(2-pyridyl)ethylJ-luro[2,3-b]-quinolin-4 (2H_)-one 25 3,9-Dihydro-9-(3-chlorophenyl)-furo[2,3-b]- quinolin-4(2H)-one 3,9-Dihydro-2-methyl-9-(3-chlorophenyl)-furo-[2,3-b] quinolin-4 (2B_)-one 2,3,4,10-Tetrahydro-10-phenyl-pyrano[2,3-b]-30 [1,8] naphthyridin-5-one, m.p. 288-290"C (dec.) 2,3,4,10-Tetrahydro-2-methyl-10-phenyl-pyrano-[2,3-b][1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(4-fluorophenyl)-pyrano-(2,3-b][1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(4-chlorophenyl)-pyrano- [2,3-b][1,8]naphthyridin-5-one, m.p. 268-270*C * 2,3,4,10-Tetrahydro-10-(3,4-dichlorophenyl)-pyrano[2,3-b][1,8]naphthyridin-5-one, m.p. >265*C 2,3,4,10-Tetrahydro-10-(4-methylphenyl)-pyrano-(2,3-b][1,8]naphthyridin-5-one, m.p. 276-279'C 2,3,4,10-Tet rahydro-10-(4-methoxyphenyl)-pyrano-(2,3-b](1,8]naphthyridin-5-one, m.p. 256-258'C 2,3,4,10-Tetrahydro-10-(3-methoxyphenyl)-pyrano-[2,3-b][1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(3-methyl-mercaptophenyl)-pyrano[2,3-b][1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-benzyl-pyrano[2,3-b]-[1,8] naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(2-phenylethyl)-pyrano-[2,3-b][1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(2-thienylmethy1)-pyrano-[2,3-b][1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(2-th i azoly1)-pyrano-[2,3-b][1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-l0-[2-(2-pyridyl)ethyl]-pyrano[2,3-b)[1,8]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(3-chlorophenyl)-pyrano-[2,3-b][1,8]naphthyridin-5-one 2,3,4 ,10-Tetrahydro-10-phenyl-pyrano[2,3-b]-quinoline-5-one 2,3,4,10-Tetrahydro-2-methyl-10-phenyl-pyrano-[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-8-chloro-10-phenyl-pyrano-[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-8-fluoro-10-pheny1-pyrano-[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-8-methoxy-10-phenyl-pyrano-[2,3-b]quinoline-5-one 2,3,4 ,10-Tetrahydro-8-ipethyl-10-phenyl-pyrano-I2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-7-chloro-1O-phenyl-pyrano-[2,3-b]quinoline-5-one 5 2,3,4,10-Tetrahydro-7-fluoro-10-phenyl-pyrano- [2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-7-methoxy-1O-phenyl-pyrano-[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-10-(4-fluorophenyl)-pyrano-10 [2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-10-(4-chlorophenyl)-pyrano-[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-10-(4-methoxyphenyl)-pyrano-[2,3-b]quinoline-5-one 15 2,3,4,10-Tet rahydro-10-(3-methoxyphenyl)- pyrano-[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-10-(3-methylmercapto-phenyl)-pyrano[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-10-benzy1-pyrano[2,3-b]-20 quinoline-5-one 2,3,4,10-Tetrahydro-10-(2-phenylethyl)-pyrano-[2,3-b]quinoline-5-one 2,3,4 ,10-Tetrahydro-10-(2-thienylmethyJ)-pyrano-[2,3-b]quinoline-5-one 25 2,3,4,10-Tetrahydro-10-(2-thiazolyl)-pyrano- [2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-10-[2-(2-pyridyl)ethyl]-pyrano[2,3-b]quinoline-5-one 2,3,4,10-Tetrahydro-10-(3-chlorophenyl)-pyrano-3q {2,3-b]quinoline-5-one 3,9-Dihydro-9-phenyl-furo[2,3-b][1,5]-naphthyridin-4-(2H)-one 3,9-Dihydro-2-methyl-9-phenyl-furo[2,3-b][1,5]-naphthyridin-4-(2HJ-one 3,9-Dihydro-2-(n-butyl)-9-phenyl-furo[2,3-b]-[1,5] naphthyridin-4-(2H_)-one 3,9-Dihydro-9-(4-fluorophenyl)-furo[2,3-b] [1,5]-naphthyridin-4-(2H_)-one 3,9-Dihydro-2-methyl-9-(4-fluorophenyl)-furo-[2,3-b][1,5]naphthyridin-4-(2£)-one 3,9-Dihydro-9-(4-chlorophenyl)—furo[2,3-b]-[1,5]naphthyridin-4-(2H)-one 3,9-Dihydro-9-(4-methoxyphenyl)-furo[2,3-b]-[1,5] naphthyridin-4-(2JB_)-one 3,9-Dihydro-9-(4-methylphenyl)-furo[2,3-b] [1,5]-naphthyridin-4-(2J_)-one 3,9-Dihydro-9-(3,4-dichlorophenyl)-furo[2,3-b] 11,5]naphthyridin-4-(2H)-one 3,9-Dihydro-9-(3-methoxyphenyl)-furo[2,3-b]-[1,5] naphthyridin-4-(2H_)-one 3,9-Dihydro-9-(3-methylmercaptophenyl)-furo-[2,3-b] [1,5] naphthyridin-4-(2H_)-one 3,9-Dihydro-9-(3-chlorophenyl)-furo[2,3-b][1,5]-naphthyridin-4-(2HJ-one 3,9-Dihydro-9-benzyl-furo[2,3-b][1,5]-naphthyridin-4-(2H)-one 3,9-Dihydro-9-(2-thienylmethyl)-furo[2,3-b]-[1,5] naphthyridin-4-(2H_)-one 3,9-Dihydro-9-(2-thiazolyl)-furo[2,3-b][1,5]-naphthyridin-4-(2H)-one 2,3,4,10-Tetrahydro-10-phenyl-pyrano[2,3-b]-[1,5]naphthyridin-5-one 2,3,4,10-Tetrahydro-2-methy1-1O-phenyl-pyrano-[2,3-b][1,5]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(4-fluorophenyl)-pyrano [2,3-b][1,5]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(4-chlorophenyl)-pyrano [2,3-b][1,5]naphthyridin-5-one 2,3,4,1O-Tetrahydro-10-(3-methoxyphenyl)-pyrano-[2,3-b][1,5]naphthyridin-5-one 2,3,4,10-Tetrahydro-10-(3-methylmercapto-phenyl)-pyrano[2,3-b][1,5]naphthyridin-5-one _ 2,3,4,1O-Tetrahydro-10-(3-chlorophenyl)-pyrano- ¥ J [2,3-b] 11,5] naphthyridin-5-one 2,3,4,1O-Tetrahydro-10-benzyl-pyrano[2,3-b]-[1,5] naphthyridin-5-one 2,3,4,1O-Tetrahydro-10-(2-thienylmethyl)-1Q pyrano-I2,3-b][1,5]naphthyridin-5-one 7,8-Dihydro-5-phenyl-furo[3*,2':5,6]pyrido-[2,3-b]pyrazin-9(5HJ-one 7,8-Dihydro-2-methy1-5-pheny1-furo[3 *,2':5,63 — pyridoI2,3-b] pyrazin-9(5H_)-one 5 7,8-Dihydro-2-(n-butyl)-5-phenyl-furo- [3* ,2*:5,6] pyrido[2,3-b] pyrazin-9(5H_)-one 7,8-Dihydro-2,3-dimethyl-5-phenyl-furo-[3' ,2' :5,6] pyrido[2,3-b] pyrazin-9(5H^)-one 7,8-Dihydro-2,3,7-trimethyl-5-phenyl-furo-20 [3' ,2' :5,6] pyrido[2,3-b]pyrazin-9(5H_)-one 7,8-Dihydro-5-(4-fluorophenyl)-furo[3',2':5,6]-pyrido[2,3-b] pyrazin-9(5j!)-one 7,8-Dihydro-2-methyl-5-(4-fluorophenyl)-furo-[3' ,2* :5,6] pyrido[2,3-b] pyrazin-9(5j!)-one 25 7,8-Dihydro-2,3-dimethyl-5-(4-fluorophenyl)- furo[3' ,2* :5,6]pyrido(2,3-b]pyrazin-9(5_H)-one 7,8-Dihydro-2,3,7-trimethyl-5-(4-fluorophenyl)-furo[3* ,2* :5,6] pyrido[2,3-b] pyrazin-9(5J3)-one 7,8-Dihydro-5-(4-chlorophenyl)-furo[3*,2':5,6]-3Q pyrido[2,3-b] pyrazin-9(5jO-one 7,8-Dihydro-5-(4-methylphenyl)-furo[3',2* s5,6] — pyrido[2,3-b] pyrazin-9(5H_)-one 7,8-Dihydro-5-(4-methoxyphenyl)-- . furo[3* ,2' :5,6]-pyrido[2,3-b] pyrazin-9(5£)-one 7 ,8-Dihydro-5-(3-methoxyphenyl)-furo[3',2':5,6]-pyrido[2,3-b]pyrazin-9(5H)-one 7,8-Dihydro-5-(3-methylmercaptophenyl)-furo-13' ,2' :5,6] pyrido[2,3-b] pyrazin-9(5E)-one 7,8-Dihydro-5-(3-chlorophenyl)-furo[3',2':5,6]-pyrido[2,3-b] pyrazin-9(5HJ-one ,7,8 ,9-Tetrahydro-5-phenyl-1 Oj^-pyrano-[3 *,2':5,6]pyrido[2,3-b]pyrazin-10-one ,7,8 ,9-Tetrahydro-7-methy 1-5-pheny 1-10J^-pyrano-[3',2*:5,6]pyridoI2,3-b]pyrazin-10-one ,7 ,8 ,9-Tetrahydro-5-(4-fluorophenyl)-10j^-pyrano[3',2':5,6]pyrido[2,3-b]pyrazin-10-one ,7,8,9-Tetrahydro-2,3-dimethyl-5-(4-fluorophenyl)-10H_-pyrano[3' ,2' :5,6] pyrido[2,3-b] pyrazin-10-one ,7,8,9-Tetrahydro-7-methyl-5-(4-fluorophenyl) 10H_-pyrano [ 3',2 •:5,6] pyrido [2,3-b] pyrazin-10-one ,7,8,9-Tetrahydro-5-(3-methoxyphenyl)-10H^ pyrano[3',2':5,6]pyrido[2,3-b]pyrazin-10-one ,7,8,9-Tetrahydro-5-(3-methylmercaptophenyl)-lOH.-pyranoO' ,2* :5,6] pyrido[2,3-b] pyrazin-10-one ,7 ,8,9-Tetrahydro-5-(3-chlorophenyl)-10H^ pyrano[J',2':5,6]pyrido[2,3-b]pyrazin-10-one ,7 ,8,9-Tetrahydro-7-methyl-5-(3-methoxyphenyl)-10H^pyrano[3',2*:5,6]pyrido[2,3-b]pyrazin 10-one ,7,8,9-Tetrahydro-7-methyl-5-(3-chlorophenyl) 10H_-pyrano[3' #2' :5,6] pyrido[2,3-b] pyrazin-10-one EXAMPLE 3 3,9-Dihydro-2-methyl-9-phenyl-furo[2,3-b][1,8]-naphthyridin-4(2H)-one A suspension of 4-hydroxy-3-(2-hydroxypropyl)-1-phenyl-1,8-naphthyridin-2(1H_)-one (1 g.) in CH2Cl2 was stirred in an atmosphere of nitrogen. To this was added pyridine (1.5 ml.). To this mixture was added a solution of S0C12 (1.5 ml.) in CH2C12 CO »1-) drop-wise over a period of 15 minutes. The mixture was stirred overnight at room temperature then water was 5 added. The CH2C12 layer was separated, dried and evaporated. Recrystallization from isopropanol yielded the product, m.p. 207-209*C.

EXAMPLE 4 -(3,4-Dichlorophenyl)-3,5-dihydro-2-methyl-furo 1 q [3,2-c][1,8]naphthyridin-4(2H)-one A solution of p-toluene sulfonic acid (5g.) in toluene (100 ml.) was prepared. To this was added 1-(3,4-dichloropheny1)-4-hydroxy-3-(2-hydroxypropyl)-1,8-naphthyridin-2( 1j[)-one (5g.) and the mixture was stirred 15 and heated to reflux in an atmosphere of nitrogen. The mixture was refluxed for 18 hrs. The resulting solution was poured into water (200 ml.), stirred for 1/2 hr. then filtered. The solids were recrystallized from isopropanol to yield the product, m.p. 273-274*C.

EXAMPLE 5 2-n-Butyl"3,5~dihydro-5-phenyl-furo- [3,2-c][1,8]naphthyridin-4(2H)-one A solution of 4-hydroxy-3-(2-hydroxyhexyl)-1-phenyl-1,8-naphthyridin-2( 1_H)-one (2g.) in 47% HBr was 25 stirred in an atmosphere of nitrogen and heated to 80*C for 4 1/2 hrs. after which time it was cooled and poured into water. The precipitate was filtered off, washed with water, dried in air, recrystallized from ethanol/ charcoal to yield the product m.p. 179-180'C.

EXAMPLE 6 2-Methyl-3,5-dihydro-5-phenyl-furo[3,2-c]-[1,8]naphthyridin-4(2H)-one A solution of 4-hydroxy-3-(2-hydroxypropyl)-1-5 phenyl-1,8-naphthyridin-2( 1J0-one (8.9 g; 0.03 mole) in 47% HBr (90 ml.) was stirred in an atmosphere of nitrogen. The solution was heated to 90*C for 4 1/2 hrs. then was allowed to cool, poured into water and was adjusted to pH 4.5 with sodium acetate. The product was 10 filtered off, washed with water, dried in air and recrystallized from CHC13/isopropanol to yield the product, m.p. 223-224*C.

EXAMPLE 7 6-Phenyl-2,3,4,6-tetrahydro-pyrano[3,2-cl -[1,8]naphthyridin-5-one A suspension of 4-hydroxy-3-(3-hydroxypropyl)-1-phenyl-1,8-naphthyridin-2( 1J!_)-one (5.67 g.) in 47% HBr (50 ml.) was stirred in an atmosphere of nitrogen and was heated to 90*C for 5 hrs. After cooling, the product was 2Q poured into water, and the pH was adjusted to 4.5 with potassium acetate. Chromatographic purification of the product on silica gel eluting with CH2CI2: 5% ether and subsequent recrystallization of the product from the relevant fractions yielded the product, m.p. 253-255*C.

EXAMPLE 8 3,5-Dihydro-5-phenyl-furo[3,2-c][1,81- naphthyridin-4(2H)-one A solution of 4-hydroxy-3-(2-hydroxyethyl)-1-phenyl-1,8-naphthyridin-2-( 1j|_)-one (10 g.) in 30% (v/v) 30 sulfuric acid (200 ml.) was heated to reflux, in an atmosphere of nitrogen, and was held at reflux until no further reaction occured (ca. 5-8 hrs.). After cooling, the solution was added slowly and carefully to an ice- cooled solution of sodium hydroxide (50% solution; 200 ml.). The mixture was allowed to stand overnight and was then*filtered. The product was washed with water, dried in air and recrystallized from dimethylformamide/water, with charcoal treatment, to yield the product, m.p. 276-277.5*C.

The following compounds may be similarly prepared by substituting the appropriate starting material and using the method of Examples 5, 6, 7 or 8. 3,5-Dihydro-5-(4-chlorophenyl)-furo[3,2-c]-[1,8] naphthyridin-4(2JH)-one, m.p. >260*C 3,5-Dihydro-2-methyl-5-(4-chlorophenyl)-furo-[3,2-c] [ 1,8] naphthyridin-4(2jO-one 3,5-Dihydro~2-^ethyl-5-( 4-chlorophenyl)-furo-(3,2-c] [1,8]naphthyridin-4(2H)-one 3,5-Dihydrp-«2'-(n-propyl)-5-( 4-chlorophenyl )-furo[3,2-c][1,8]naphthyridin-4(2H)-one 3,5-Dihydrp-2-(n-butyl)-5-(4-chlorophenyl)-furo[3,2-c] [1 ,8] naphthyridin-"4(2JO-one 3,5-Dihydro-2-ethyl-5-phenyl-furo[3,2-c][1,8]-naphthyridi n-4(2H)-one 3,5-Dihydro-2- (n-prooy.l )-5-phenyl-f uro [3,2-c] -[1,8] naphthyridin-4(2J0-one 3,5-Dihydro-2-(iso-butyl)-5-phenyl-furo[3,2-c]-[1,8] naphthyridin-4(2H_)-qne 3,5-Dihydro-2,2^dimethyl-5-phenyl-furo[3,2-c]-[1,8] naphthyridin-4(2J_)-«qne,m.p. 216-217 .5*C 3,5-Dihydro-5^(4-fluorophenyl)-furo[3,2-c]-[1,8] naphthyridin-4(2jH)"0ne, m.p. >260*C 3,5-Dihydro-2-methyl-5<- (4-fluorophenyl )-f uro-[3,2-c][1,8]naphthyridin-4(2HJ-one, m.p. 252-254'C 3,5-Dihydro-2-ethyl-5-<*(4-fluorophenyl)-furo-[3,2-c] [1,8] naphthyridin-4(2H_Hone 3,5-Dihydro-2-(n-prQpyl)-5-(4-fluorophenyl)-furo[3,2-c] [1,8] naphthyridin-4(2J_)-one 3,5-Dihydro-2-(n-butyl)-5-(4-fluorophenyl)-furo-[3,2-c] [1,8] naphthyridin-4 (2j!)-one 3,5-Dihydro-5-(4-methylphenyl)-furo[3,2-c]-[1,8] naphthyridin-4(2H^)-one, m.p. 258.5-260*C 5 3,5-Dihydro-2-methyl-5-(4-methylphenyl)- furo[3,2-c] [1,8] naphthyridin-4 (2H_)-one 3,5-Dihydro-2-(n-butyl)-5-(4-methylphenyl)-furo[3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(4-methoxyphenyl)-furo[3,2-c] -10 [1,8]naphthyridin-4(2HJ-one, m.p. 282-284'C 3,5-Dihydro-2-methyl-5-(4-methoxyphenyl)-furo-[3,2-c] [1,8] naphthyridin-4(2jH)-one 3,5-Dihydro-2-(n-butyl)-5-(4-methoxyphenyl)-furo[3,2-c][1,8]naphthyridin-4(2E)-one 15 3,5-Dihydro-5-(3,4-dichlorophenyl)-furo[3,2-c]- [1,8] naphthyridin-4(2jU-one, m.p. 256.5-258"C 3,5-Dihydro-2-methyl-5-(3,4-dichlorophenyl)-furo[3,2-c] [1,8] naphthyridin-4(2H_)-one, 273-274#C 3,5-Dihydro-2-(n-butyl)-5-(3,4-dichlorophenyl)-20 furo[3,2-c] [ 1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(3-methoxyphenyl)-furo[3,2-c]-[1,8]naphthyridin-4(2HJ-one 3,5-Dihydro-2-methyl-5-(3-methoxyphenyl)-furo-[3,2-c][1,8]naphthyridin-4(2H)-one, m.p. >260*C 25 3,5-Dihydro-2-(n-butyl)-5-(3-methoxyphenyl)- furo[3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(3-methylmercaptophenyl)-furo-[3,2-c][1,8]naphthyridin-4(2HJ-one 3,5-Dihydro-2-methyl-5-(3-methylmercapto-30 phenyl)-furo[3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-2-(n-butyl)-5-(3-methylmercapto-phenyl)-furo[3,2-c][1,8]naphthyridin-4(2JO-one 3,5-Dihydro-5-(3-methylsulfinylphenyl)-furo-[3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-2-methyl-5r(3-methylsulf inyl-phenyl)-furo[3,2-c] [1 ,8] naphthyridin-4 (2JH-one 3,5-Dihydro-2-(n-butyl)-5-(3-methylsulfinyl-phenyl)-furo[3,2-c] [1,8] naphthyridin-4 (2H_)-one 5 3,5-Dihydro-5-(3-methylsulfonylphenyl)-furo- [3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-2-methyl-5-(3-methylsulfonyl-phenyl)-furo[3,2-c] [1,8] naphthyridin-4(2j0-one 3,5-Dihydro-2-(n-butyl)-5-(3-methylsulfonyl-10 phenyl)-furo[3,2-c] [1,8] naphthyridin-4(2ji)-one 3,5-Dihydro-5-(3,5-dichlorophenyl)-furo[3,2-c]-[1,8] naphthyridin-4(2H_)-one, m.p. 283-284"C 3,5-Dihydro-2-methyl-5-(3,5-dichlorophenyl-f uro [3,2-c][1,8] naphthyridin-4 (2H_)-one, m.p. 254-256#C 15 3,5^Dihydro-5-(2,3-dichlorophenyl-furo[3,2-c]- [1,8] naphthyridin-4(2H_>-one 3,5-Dihydro-2-methy1-5-(2,3-di chloropheny1)-furo[3,2-*c] [1,8] naphthyridin~4(2jn-one 3,5-Dihydro-5-(2,5-dichlorophenyl)furo[3,2-c]-20 [1 *8] naphthyridin-4(2j!)-one 3,5-Dihydro-2-methyl-5-(2,5-dichlorophenyl)-furo[3,2-c] [1,8] naphthyridin'-4(2H)-one 3,5-Dihydro-5-(3-chloro^4-fluorophenyl)-furo-[3,2-c] [1,8] naphthyridin-4(2HWone 25 3,5-Dihydro-2-methyl-5-(3-chloro-4-fluoro phenyl )-furo[3,2-c][1,8]naphthyridin-4(2HJ-one 3 ,5-Dihydro-2'-methyl-!-5-{ 3-trif luoromethylphenyl )-f uro [3,2-c] [1,8J naphthyridin-4(2HJ-one 3,5-Dihydro-2^-methyl-5- (3-trif luororaethyl-30 phenyl)-furo[3,2-c] [1,8] naphthyridin-4(2JH)-one 3,5-Dihydro-5^(3-chlorophenyl)-furo[3,2-c] [1,8]-naphthyridin-4(2j_)-one, m.p. 205-207#C 3,5-Dihydro-2«methyl-5-(3-chlorophenyl)-furo [3,2-c] [1,8] naphthyridin-4(2H_)-one, m.p. 254-256"C 3,5-Dihydro-5-benzyl-furo[3,2-c][1,8]-naphthyridin-4 (2H_)-one 3,5-Dihydro-2-methyl-5-benzyl-furo[3,2-c][1,8]— naphthyridin-4 (2jH-one 5 3,5-Dihydro-5-(2-phenylethyl)-furo[3,2-c][1,8]- naphthyr idin-4 (2j!)-one 3,5-Dihydro-2-methyl-5-(2-phenylethyl)-furo-[3,2-c][1,8]naphthyridin-4(2H)-one 3,5-Dihydro-5-(1-phenylethyl)-furo[3,2-c][1,8]-•j o naphthyridin-4 (2H_) -one 3,5-Dihydro-2-methyl-5-(1-phenylethyl)-furo-[3,2-c][1,8]naphthyridin-4(2H)-one 3,5-Dihydro-5-(2-thienylmethyl)-furo[3,2-c]-[1,8] naphthyridin-4 (2j0-one 15 3,5-Dihydro-2-methyl-5-(2-thienylmethyl)-furo- [3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(2-thiazolyl)-furo[3,2-c][1,8]-naph thyr idin-4 (2jJ)-one 3,5-Dihydro-2-methyl-5-(2-thiazolyl)-furo-20 [3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(2-pyridyl)-furo[3,2-c][1,8]-naph thy ridin-4 (2jy -one 3,5-Dihydro-5-[2-(2-pyridyi)ethylJ-turo[3,2-c]-[1,8] naphthyridin-4(2JB)-one 25 3,5-Dihydro-2-methyl-5-(3-methylsulfonylamino- phenyl)-furo[3,2-c][1,8] naphthyridin-4 [2j!]-one, m.p. 258-260*C 3,5-Dihydro-5-(3-methylsulfonylaminophenyl)-furo[3,2-c][1,8]-naphthyridin-4[2H]-one, m.p. >260*C 30 3,5-Dihydro-5-phenyl-furo[3,2-c]quinolin- 4 (2HJ -one 3,5-Dihydro-2-methyl-5-phenyl-furo[3,2-c]-quinolin-4(2H_)-one, m.p. 195-197'C 3,5-Dihydro-2-(n-butyl)-5-phenyl-furo[3,2-c]-35 quinolin-4 (2H_)-one 3 ,5-Dihydro-8-chloro-5r-phenyl-furo[3,2-c]-quinolin-4 (2H_) -one 3,5-Dihydro-2-methyl-8-chloro-5-phenyl-furo-[3,2-c]quinolin-4(2H)-one 5 3,5-Dihydro-8-fluoro-5-phenyl-furo[3,2-c]- quinolin-4(2H)-one 3,5-Dihydro-2-methyl-8-fluoro-5-pheny1-furo-[3,2-c] quinolin-4(2j[)-one 3,5-Dihydro-8-methoxy-5-phenyl-furo[3,2-c]-10 quinolin-4 (2H_)-one 3,5-Dihydro-2-methyl-8-methoxy-5-phenyl-furo-[3,2-c]quinolin-4(2J0 -one 3,5-Dihydro-7-chloro-5-phenyl-furol3,2-c]-quinolin-4(2H_)-one 15 3,5-Dihydro-2-methyl-7-chloro-5-phenyl-furo- [3,2-c] quinolin-4(2H_)-one 3,5-Dihydro-7-fluoro-5-phenyl-furo[3,2-c]-qu i nol i n-4 (2H_) -one 3,5-Dihydro-2-methyl-7-fluoro-5-phenyl-furo-20 [3,2-c] quinolin-4(2H_)-one 3,5-Dihydro-5-(4-fluorophenyl)furo[3,2-c]-quinolin-4 (2j!)-one 3,5-D ihydro-2-methy1-5-(4-f1uorophe ny1)-f uro-[3,2-c] quinolin-4 (2jO-one 25 3,5-Dihydro-5-(3-methoxyphenyl)-furo[3,2-c]- quinolin-4(2HJ -one 3,5-Dihydro-2-methyl-5-(3-methoxyphenyl)-furo-[3,2-c] quinolin-4(2J_)-one 3,5-Dihydro-5-(3-methylmercaptophenyl)-furo-30 [3,2-c] quinolin-4 (2j!)-one 3,5-Dihydro-2-methyl-5-(3-methylmercapto-phenyl )-f uro 13,2-c] quinolin-4 (21!)-one 3,5-Dihydro-5-(3,5-dichlorophenyl)-furo[3,2-c] qu i noli n-4(2E)-one 3,5-Dihydro-2-methyl*5-(3,5-dichlorophenyl)-furo|3,2-c]quinolin-4(2H)-one 3,5-Dihydro-2-methy1-5-(3-chlorophenyl)-furo-[3,2-c] quinolin-4 (2H_)-one 3,5-Dihydro-5-(3-chlorophenyl)-furo[3,2-c]-qui nol in-4 (2H_) -one 3,5-Dihydro-5-(3-trifluoromethylphenylJ-furo-JS^-clquinolin^^HJ-one 3,5-Dihydro-2-methyl-5-(3-tri fluoromethylphenyl )-furo[3,2-c]quinolin-4(2HJ-one 3 ,5-Dihydro-5-(3-chloro-4-f1uoropheny1)-furo-[3,2-c]quinolin-4(2H)-one 3 ,5-Dihydro-2-methyl-5-(3-chloro-4-fluorophenyl ) -f uro [ 3,2-c] quinolin-4 (2JB) -one 3,5-Dihydro-5-benzyl-furo[3,2-c]quinolin- 4(2H)-one 3,5-Dihydro-2-methyl-5-benzyl-furo[3,2-c]-quinolin-4(2H>)-one 3 ,5-Dihydro-5-(2-phenylethyl)-furo[3,2-cJ-qu i nol i n-4(2E)-one 3 ,5-Dihydro-5-(2-thienylmethyl)-furo[3,2-c]-quinolin-4(2H)-one 3,5-Dihydro-5-(2-pyridyl)-furo[3,2-c]quinolin- 4(2_H)-one 3,5-Dihydro-[2-(2-pyridyl)ethyl]-5-furo[3,2-c] quinolin-4 (2J3_)-one 2,3,4,6-Tetrahydro-6-phenyl-pyrano[3,2-c][1,8] naphthyridin-5-one, m.p. 253-255#C 2,3,4,6-Tetrahydro-2-methyl-6-phenyl-pyrano-[3,2-c][1,8]naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(4-fluorophenyl)-pyrano-[3,2-c][1,8]naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(4-chlorophenyl)-pyrano-[3,2-c]11,8]naphthyridin-5-one, m.p. 236-237*C -40 2,3 ,4 ,6-Tetrahydro-6-(.3,4-dichlorophenyl)-pyranc»I3,2-c] [1,8] naphthyridin-5-one, m.p. >265*C 2,3,4,6-Tetrahydro-6-(4-methylphenyl)-pyrano-[3,2-c][1,8]naphthyridin-5-one, m.p. >280"C 5 2,3,4,6-Tetrahydro-6-(4-methoxyphenyl)-pyrano- [3,2-c][1,8]naphthyridin-5-one, m.p. >270*C 2,3,4,6-Tetrahydro-6-(3-methoxyphenyl)-pyrano-[3,2-c][1,8]naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(3-chlorophenyl)-pyrano-10 [3,2-c][1,8]naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(3-methylmercaptophenyl)-pyrano[3,2-c][1,8]naphthyridin-5-one 2,3 ,4,6-Tetrahydro-6-(3,5-dichlorophenyl)-pyrano-[3,2-c][1,8]naphthyridin-5-one -j5 2,3,4 ,6-Tetrahydro-6-(2,3-dichlorophenyl)- pyrano[3,2^-c] [1,8] naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(2,5-dichlorophenyl)-pyrano[3,2-c][1,8]naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(3-chloro-4-fluorophenyl)-20 pyrano[3,2-c][1,8]naphthyridin-5-one 2,3,4,6-"Tetrahydro-6-( 3-trif luoromethylphenyl) -pyrano[3,2-c] [1,81 naphthyridin-»5-one 2,3,4,6-Tet rahydro->6-t>enzyl-pyrano- [ 3,2-c] -[1,8]naphthyridin-5-one 25 2,3,4,6-Tetrahydro-6-(2^phenylethyl)-pyrano- [3,2-c] [1,8] naphthyridin-5*-one 2,3,4,6-Tetrahydro-6-(2-thienylmethyl)-pyrano-[3,2-c][1,8]naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(2-thiazolyl)-pyrano-30 [3,2-c] [1,8] naphthyridin<-5^one 2,3,4,6-Tetjrahydro-6- (2- [2-pyridyl] ethyl-pyrano[3,2-c][1,8]naphthyridin-5-one 2,3,4,6-Tetcahydro-6-phenyl-pyrano[3,2-c]-quinolin-5-one 2,3,4,6-Tetrahydro-2-i^ethy1-6-phenyl-pyrano-[3,2-fc]quinolin-5-one 2,3,4,6-Tetrahydro-9-chloro-6-phenyl-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-9-fluoro-6-phenyl-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-9-methoxy-6-phenyl-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-9-methy1-6-pheny1-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-8-chloro-6-phenyl-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-8-fluoro~6-phenyl-pyrano-(3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-8-methoxy-6-pheny1-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(4-fluorophenyl)-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(4-chlorophenyl)-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(4-methoxyphenyl)-pyrano [3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(3-chlorophenyl)-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(3-methoxyphenyl)-pyrano [3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(3-methylmercaptophenyl) pyrano[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-benzyl-pyrano-[3,2-c]-quinolin-5-one 2,3,4,6-Tetrahydro-6-(2-phenylethyl)-pyrano-[3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(2-thienylmethyl)-pyrano [3,2-c]quinolin-5-one 2,3,4,6-Tetrahydro-6-(2-thiazolyl)-pyrano-[3,2-clquinolin-5-one 2,3,4,6-Tetrahydro-6-[2-(2-pyridyl)ethyl]-pyrano[3,2-c]quinolin-5-one 3,5-Dihydro-5-phenyl-furo(3,2-c][1,5]-naphthyridin-4 (2H_)-one 3,5-Dihydro-2-methyl-5-phenyl-furo[3,2-c][1,5]-naphthyridin-4 (2H_)-one 3,5-Dihydro-2-ethyl-5-phenyl-furo[3,2-c][1,5]-naphthyr idin-4 (2H_) -one 3,5-Dihydro-2-(n-butyl)-5-pheny1-furo[3,2-c]-[1,5]naphthyridin-4(2HJ-one 3,5-Dihydro-5-(4-chlorophenyl)-furo[3,2-c] [1,5]-naphthyridin-4 (2H_)-one 3,5-Dihydro-2-methyl-5-(4-chlorophenyl)-furo-[3,2-c] [1,5] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(4-fluorophenyl)-furo13,2— c][1,5]-naphthyridin-4(2HJ-one 3,5-Dihydro-2-methyl-5-(4-fluorophenyl)-furo-[3,2-c] [1,5] naphthyridin-4(2_H_)-one 3,5-Dihydro-5-(4-methylphenyl)-furo[3,2-c] [1,5]-naphthyridin-4(2H[)-one 3,5-Dihydro-5-(4-methoxyphenyl)-furo[3,2-c]-[1,5] naphthyridin-4 (2H_)-one 3,5-Dihydro-5-(3,4-dichlorophenyl)-furo[3,2-c]-[1,5] naphthyridin-4 (2j0-one 3,5-Dihydro-5-(3-methoxyphenyl)-furo[3,2-c]-[1,5] naphthyridin-4(2H_)-one 3,5-Dihydro-2-methy1-5-(3-methoxyphenyl)-furo-[3,2-c][1,5]naphthyridin-4(2H)-one 3,5-Dihydro-5-(3-methylmercaptophenyl)-furo-[3,2-c] [1,5] naphthyridin-4(2H_)-one 3,5-Dihydro-2-methyl-5-(3-methylmercapto-phenyl)-furo[3,2-c] [1,5] naphthyridin-4(2H[)-one 3,5-Dihydro-5-(3-chlorophenyl)-furo[3,2- c][1,5]-naphthyridin-4(2H)-one 3,5-Dihydro-2-methyl-5-(3-chlorophenyl)-furo-[3,2.-cl 11,51 naphthyridin-4 (2H_) -one 3,5-Dihydro-5-benzyl-furo[3,2-c]11,51-naphthyridin-4 (2H_) -one 3,5-D ihydro-5-(2-thienylmethyl)-f uro[3,2-c]-[1,5] naphthyridin-4 (2H_)-one 3,5-Dihydro-5-(2-thiazolyl)-furo[3,2-c][1,5]-naphthyridin-4 (2H_)-one 3,5-Dihydro-5-(2-pyridyl)-furo[3,2-c][1,5]-naphthyr idin-4 (2H_)-one 3,5-Dihydro-5-[2-(2-pyridyl)ethyl]-furp-[3,2-c] [1,51 naphthyridin-4(2HJ-one 2,3,4,6-Tetrahydro-6-phenyl-pyrano[3,2-c][1,5]-naphthyridin-5-one 2,3,4,6-Tetrahydro-2-methyl-6-phenyl-pyrano-[3,2-c][1,51naphthyridin-5-one 2,3,4,6-Tetrahydrp-6-(4-fluorophenyl)-pyrano-[3,2-c][1,5]naphthyridin-5-pne 2,3,4,6-Tetrahydrp-6-(4-chlprpphenyl)-pyranp-[3,2-c][1,5]naphthyridin-5-pne 2,3,4,6-Tetrahydrp-6-{3,4-dichlprpphenyl)-pyranp[3,2-c][1,5]naphthyridin-b-pne 2,3,4,6-Tetrahydrp-6-(4-methylphenyl)-pyranp-[3,2-c][1,5]naphthyridin-5-pne 2,3,4,6-Tetrahydrp-6-(4-methpxyphenyl)-pyranp-[3,2-c][1,5]naphthyridin-5-pne 2,3,4,6-Tetrahydrp-6-(3-methPxyphenyl)-pyranp-[3,2-c][1,5]naphthyridin-5-pne 2,3,4,6-Tetrahydrp-6-(3-methylmercaptppheny1)-pyranp[3,2-c][1,5]naphthyridin-5-pne 2,3,4 ,6-Tetrahydrp-6-(3-chlprpphenyl)-pyranp-[3,2-c][1,5]naphthyridin-5-pne 2,3,4,6-Tetrahydrp-6-benzy1-pyranp-[3,2-c]-[1,5]naphthyridin-5-pne 2,3,4,6-Tetrahydro-6-(2-phenylethyl)-pyrano-[3,2,-c.j [1,5] naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(2-thienylmethyl)-pyrano-[3,2-c][1,5]naphthyridin-5-one 5 2,3,4,6-Tetrahydro-6-(2-thiazolyl)-pyrano- [3,2-c][1,5]naphthyridin-5-one 2,3,4,6-Tetrahydro-6-(2-[2-pyridyl]ethyl)-pyrano[3,2-c][1,5]naphthyridin-5-one 7,8-Dihydro-5-phenyl-furo[2',3*:4,5]pyrido-10 [2,3-b] pyrazin-6(5H_)-one 7,8-Dihydro-8-methyl-5-phenyl-furo[2',3*:4,5]— pyrido[2,3-b] pyrazin-6(5j[)-one 7,8-Dihydro-8-(n-butyl)-5-pheny1-furo-[2' ,3' :4,5]pyrido[2,3-b]pyrazin-6(5jO-one 7,8-Dihydro-5-(4-fluorophenyl)-furo[2',3* s4,5] — pyrido[2,3-b] pyrazin-6(5H_)-one 7,8-Dihydro-8-methyl-5-(4-fluorophenyl)-furo-[2' ,3' :4,5] pyrido[2,3-b] pyrazin-6(5_H)-one 7,8-Dihydro-2,3-dimethyl-5-(4-fluorophenyl)-20 furo[2* ,3' :4,5]pyrido[2,3-b]pyrazin-6(5H_)-one 7,8-Dihydro-2,3,8-trimethyl-5-(4-fluorophenyl)-furo[2v ,3* :4,5] pyrido[2,3-bj pyrazin-6(5H[)-one 7,8-Dihydro-5-(4-chlorophenyl)-furo[2*,3* s4r5] — pyrido[2,3-b] pyrazin-6(5J0-one 25 7,8-Dihydro-5-(4-methylphenyl)-furo[2',3*:4,5]- pyrido[2,3-b] pyrazin-6( 5_H)-one 7,8-Dihydro-5-(4-methoxyphenyl)-furo[2' ,3' :4,5]-pyrido[2,3-b]pyrazin-6(5H_)-one 7,8-Dihydro-5-(3-methoxyphenyl)-30 furo[2' ,3' :4,5]-pyrido[2,3-b]pyrazin-6(5JB_)-one 7,8-Dihydro-8-methyl-5-(3-methoxyphenyl)-furo-[2' ,3' :4,5]pyrido[2,3-b]pyrazin-6(5H_)-one 7,8-Dihydro-2,3-dimethyl-5-(3-methoxyphenyl)-furo[2' ,3* :4,5] pyrido[2,3-b] pyrazin-6(5H^)-one 35 7,8-Dihydro-5-(3-methylmercaptophenyl)-furo- [2' ,3' : 4,5] pyrido [2,3-b] pyrazin-6 (5J3)-one 7,8-Dihydro-8-methyl-5-(3-methylmercaptophenyl) -furo [2',3 *: 4,5] pyrido [2,3-b] pyrazin-6 (5jH)-one 7,8-Dihydro-2 f3-dimethyl-5-(3-methylmercaptophenyl )-furo12',31:4,5]pyrido[2,3-b]pyra z i n-6(5H)-one 7,8-Dihydro-5-(3-chlorophenyl)-furo-12* ,3':4,5]-pyrido[2„3-b]pyrazin-6(5H_)-one 7,8-Dihydro-8-methyl-5-(3-chlorophenyl)-furo-(2',3* s4,5]pyrido[2,3-b]pyrazin-6(5H)-one 7,8-Dihydro-2,3-diraethyl-5-(3-chlorophenyl)-furo-[2' ,3* s4,5]pyrido[2,3-b]pyrazin-6(5JB)-one ,7,8,9-Tetrahydro-5-phenyl-6j^-pyrano-(2',3*:4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-9-methyl-5-phenyl-6H_-pyrano-[2*,3':4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tet rahydro-5-(4-f luorophenyl) -6j£-pyrano-[2' ,3' s4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-2,3-dimethy1-5-(4-fluorophenyl ) -6j^-pyrano- [ 2', 31:4,5] pyrido 12,3-b] pyrazin-one ,7,8,9-Tetrahydro-5-(4-chlorophenyl)-6H^ pyrano-12',3':4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tet rahydro-5-(4-methy1phenyl)-6H-pyrano-[2',3':4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-5-(4-methoxyphenyl)-6jH pyrano[2*,3':4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-5-(3-methoxyphenyl)-6j^-pyrano[2',3':4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-2,3-dimethyl-5-(4-fluorophenyl )-6J£-pyrano-[21,3':4,5] pyrido [2,3-b] pyrazin-6-one ,7,8,9-Tetrahydro-5-(3-methylmercaptophenyl)-6J.-pyrano[2* ,3* i4,5]pyrido[2,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-2,3-dimethy1-5-(4-fluorophenyl )-6Jh-pyrano-[2' ,3' :4,5] pyrido 12,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-5-(3-chloropheny 1)-6JT-pyrano-12',3':4,5] pyrido12,3-b]pyrazin-6-one ,7,8,9-Tetrahydro-2 ,3-dimethyl-5-(3-chloro-phenyl )-6H>-pyrano-I2* ,3* :4,5]pyrido[2,3-b] pyrazin-6-one EXAMPLE 9 5-(3,4-Dichlorophenyl)-3 ,5-dihydro-2-methyl- furo[3,2-c] [1,8] naphthyridin-4(2H)-one To a solution of 9-(3,4-dichlorophenyl)-3,9-dihydro-2-methyl-furo[2,3-b] [1,8] naphthyridin-4 (2H_)-one (125 mg.) (prepared as in example 2) in dimethylacetamide 10 (20 ml.) in an atmosphere of nitrogen was added sodium iodide (250 mg.). The solution was refluxed for 4 hrs., and it was poured over ice-water, filtered, dried and recrystallized from isopropanol to yield the desired product, m.p. 273-274*C.

EXAMPLE 10 A mixture of 4-hydroxy-3-(2'-hydroxyethyl) 1-phenyl-1,8-naphthyridin-2( 1j!)-one (3 g.) and 2,4-bis (4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (also known as Lawesson's Reagent) (4.3 g.) in toluene 20 (100 ml) was stirred in an atmosphere of nitrogen and heated to reflux. The mixture was refluxed for 20 hr. after which it was cooled, evaporated, dissolved in CH2C12, washed with water, dried, and chromatographed over silica gel, eluting with increasing concentrations 25 of ethyl acetate (0-5%) in CH2Cl2* Three products were isolated and characterised as follows: 1st compound eluted: 3,5-Dihydro-5-phenyl-thieno[3,2-c][1,8]naphthyridin-4[2H]-thione, m.p. 275-276.5'C 2nd compound eluted: 3,5-Dihydro-5-phenyl-furo[3,2-c][1,8] naphthyridin-4[2H]-thione, m.p. 243-245.5BC. 3rd compound eluted: 3,9-Dihydro-9-phenyl-thieno[7,3-15] [1,8]naphthyridin-412HJ-thione, m.p. 264-266*C. (dec) In a similar manner, application of this procedure to other compounds having structural formula II would lead to the preparation of analogous products to those described in this Example.

EXAMPLE 11 3,5-Dihydro-5-(4-methoxyphenyl)-furo- [3,2-c][1,8]naphthyridin-4(2H)-one A solution of 3,9-dihydro-9-(4-methoxyphenyl)-furo[2,3-b] [1 ,8] naphthyridin-4(2H_)-one (1 g.) and sodium iodide (1 g.) in dry dimethylacetamide (10 ml.) was heated to 70"C for 4 hr in a nitrogen atmosphere. The product was cooled, poured over ice-water, filtered, dried and recrystallized from CH2CI2 to yield the desired product, m.p. 282-284*C.

Essentially any of the products, prepared according to the procedures of Examples 1 and 2, and in which a methylene group is next to the ring oxygen atom may be converted by this process into the products which may otherwise be prepared •icccrc'ing to the procedures of Examples 5, 6, 7 and 8.

EXAMPLE 12 3,5-Dihydro-5-phenyl-furo[3,2-c][1 ,8]- naphthyridine-4(2H)-thione A suspension of 3,5-dihydro-5-phenyl-furo-[3,2-c][1,8] naphthyridin-4(2H)-one (3 g.) and 2,4-bis- (4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's Reagent; 5 g.) in dry toluene (100 ml.) was stirred in an atmosphere of nitrogen and heated to reflux for 6 hrs. After cooling, the organic layer was washed with water, dried and evaporated. The product was purified by chromatography ovet^ silica gel in CH2CI2 containing increasing amounts of ethyl acetate (0-5%). The fractions containing pure product were combined, evaporated, suspended in ethanol, filtered and dried to 5 yield the desired product, m.p. 242-244.5*C.

In a similar manner, other compounds produced according to Examples 5, 6, 7 or 8 may be converted to their thione analogs by this process.

EXAMPLE 13 3,9-Dihydro-9-phenyl-thieno[2,3-b][1,8]- naphthyridin-4(2H)-one A solution of 3,5-dihydro-5-phenyl-furo-[3,2-c]-[1,8] naphthyridin-4 (2H.)-thione (500 mg.) and sodium iodide (500 mg.) in dry dimethylacetamide (5 ml.) was 15 stirred in an atmosphere of nitrogen and heated at 125* for 2 hr. After cooling, the solution was poured into ice-water, filtered, washed with water and dried to yield the desired product, m.p. 260-261'C.

Similarly may be prepared other such 20 derivatives from the corresponding starting materials prepared according to the method o* Example 12.

EXAMPLE 14 -Phenyl-furo[3,2-c][1,8]naphthyridin-4[5H]-one A mixture of 3,5-dihydro-5-phenyl-furo-[3,2-c]-25 [1,8]-naphthyridin-4[2H]-one (2 g.) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ; 2 g.) in dry toluene (50 ml.) was stirred in an atmosphere of nitrogen and heated to reflux. Refluxing was continued for 20 hrs. After cooling somewhat the mixture was evaporated, dissolved in 30 CH2Cl2/ filtered and chromatographed on silica gel eluting with increasing concentrations of ethyl acetate in CH2CI2 (0-10%). Evaporation of the relevant fractions and recrystallization from acetonitrile yielded the desired product, m.p. 245-247'C.

In a similar manner, any of the tricyclic-dihydro-furo derivatives may be oxidized to the corresponding furo-derivative.

EXAMPLE 15 3,9-Dihydro-9-phenyl-furo[2,3-b][1 ,8]- naphthyridin-4(2H)-thione To a stirred suspension of 3,9-dihydro-9-phenyl-furo[2,3-b][1,8]naphthyridin-4(2H)-one(1g.) in dry toluene (40ml.) at 55#C, under an atmosphere of dry nitrogen, was added a suspension of 2,4-bis,(4-methoxy-phenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's Reagent; 0.8g) in dry toluene (10ml.). The reaction was followed by t.l.c. (silica gel/CH2Cl2:5% Methanol) and warming was continued until no starting material remained (ca. 2-1/2 hr.). Toluene was removed under reduced pressure and the product was dissolved in CH2Cl2> The solution was separated by chromatography on silica gel eluting with increasing concentrations of ethyl acetate in CH2CI2 (2%-5%). The desired product was obtained as an orange-yellow solid, m.p. ca. 273-275*C (dec.).

Similarly, application of this procedure to other compounds having structural formula I", prepared according to the procedures of Examples 1 or 2, will produce the thione analogs of compounds described in those examples.

EXAMPLE 16 3,5-Dihydro-5-phenyl-thieno[3,2-c][1,8]-naphthyridin-4(2H)-one A solution of 3,5-dihydro-9-phenyl-furo-12,3-b] (1,8]-naphthyridin-412HJ-thione (500mg.) and sodium iodide (500mg.) in dry dimethylacetamide (5ml.) was stirred in an atmosphere of nitrogen and heated to 100*C for 2 hrs. After cooling,, the solution was poured into ice water, filtered, washed with water dried and recrystallized from isopropanol to yield the desired product, m.p. 277-279*C.

In a similar manner may be prepared other such derivatives from the corresponding starting materials prepared according to the method of Example 15.

Examples of such compounds are: 3,5-Dihydro-2-methyl-5-phenyl-thieno[3,2-c] [1,8]-naphthyridin-4(2j!)-one 3,5-Dihydro-5-(4-fluorophenyl)-thieno[3,2-c][1,8]-naphthyridin-4(2H)-one 3,5-Dihydro-2-methyl-5-(4-fluorophenyl)-thieno [3,2-cl 11,8] naphthyridin-4(2ji)-one 3,5-Dihydro-5-(3-chlorophenyl)-thieno[3,2-c] [1,8]-naphthyridin-4 (2H_)-one 3,5-Dihydro-2-methyl-5-(3-chlorophenyl)-thieno 13,2-c] [1,8]naphthyridin-4(2ja)-one 3,5-Dihydro-5-(3-methoxyphenyl)-thieno[3,2-c] [1,8]-naphthyridin-4 (2H_)-one 3,5-Dihydro-2-methyl-5-(3-methoxyphenyl)-thieno-I3,2-c] 11,8] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(3-methylthiophenyl)-thieno-13,2-c] [1,8] naphthyridin-4 (2jO-one 3,5-Dihydro-2-methyl-5-(3-methylthiophenyl)-thieno[3,2-c] [1,8] naphthyridin-4(2H_)-one 3,5-Dihydro-5-(3-trifluoromethylphenyl)-thieno[3,2-c][1,8]naphthyridin-4(2JH -one 3,5-Dihydro-2-methyl-5-(3-trifluoromethylphenyl )-thieno [3 ,2-c] [1,8] naphthyridin-4(2jO-one 3,5-Dihydro-5-(3,5-dichlorophenyl)-thieno-[3,2-c] [1,8] naphthyridin-4(2ji)-one 3,5-Dihydro-2-methyl-5-(3,5-dichlorophenyl)-thieno-[3,2-c] [1,8] naphthyridin-4(2jl)-one -51-, 3,5-Dihydro-5-(3-chloro-4 -fluorophenyl)-thieno-[3,2-c]11,8]naphthyridin-4(2H)-one 3,5-Dihydro-2-methyl-5-(3-chloro-4-fluorophenyl )-thieno[3,2-c][1,8]naphthyridin-4(2H)-one 5 3,5-Dihydro-5-(4-chlorophenyl)-thieno[3,2-c] [1,8]-naphthyridin-4(2B0-one 3,5-Dihydro-5-(4-methylphenyl)-thieno[3,2-c] [1,8]-naphthyridin-4(2H)-one 3,5-Dihydro-5-(4-methoxyphenyl)-thieno[3,2-c] 10 [1,8]-naphthyridin-4 (2j0-one 3,5-Dihydro-5-(3,4-dichlorophenyl)-thieno-[3,2-c][1,8]naphthyridin-4(2H)-one 3,5-Dihydro-5-(3-methylsulfinylphenyl)-thieno-[3,2-c][1,8]naphthyridin-4(2HJ-one 15 3,5-Dihydro-5-(3-methylsulfonylphenyl)-thieno- [3,2-c][1,8]naphthyridin-4(2HJ-one EXAMPLE 17 7-Phenyl-3 ,4 ,5 ,7-tetrahydro-oxepino[3,2-c][1,8] naphthyridin-6(2F)-one 20 The mono-mesylate (1 g.) from Preparative Example 7 was dissolved in DMF (20 ml.) at R.T. and cesium carbonate (2 g.) was added. The reaction was followed by HPLC or TLC until essentially no starting material remained (ca. 1 hr.). A mixture of two products 25 was formed. The total product was poured into ice/water and the product was filtered off. The two products were * separated by column chromatography [Whatman LPS-2 silica gel; CH2CI2 + 0-5% MeOH] or by preparative reversed-phase HPLC [Whatman Partisil 40; ODS-3; Magnum 40 column] and 30 the desired fractions isolated. Evaporation yielded 7- phenyl-3,4,5,7-tetrahydro-oxepino[3,2-c][1,8] naphthyridin-6(2H>)-one m.p. 180-181 "C.

The following compounds may be prepared similarly by substituting the appropriate starting material from Preparative Example 6. 7-(3-Aminophenyl)-3,4,5,7-tetrahydro-oxepino-5 [3,2-c] [ 1 #8J-naphthyridin-6 (2jO-one; 7-(3-Methylsulfonylaminophenyl)-3,4,5,7-tetrahydro-oxepino-[3,2-c] [1,8]-naphthyridin-6 (2j0-one; 7-(3-Formylaminophenyl)-3,4,5,7-tetrahydro-oxepino-[3,2-c] II ,8]-naphthyridin-6 (2J0-one; 10 7-(3-Acetylaminophenyl)-3,4,5,7-tetrahydro- oxepino-[3,2-c] [1,8]-naphthyridin-6 (2j!)-one; 7-(3-Oxalylaminophenyl)-3,4,5,7-tetrahydro-oxepino-[3,2-c] [1,8.1 -naphthyridin-6(2JH)-one; 7-(4-Chlorophenyl)-3,4,5,7-tetrahydro-oxepi no[3,2-c] •j 5 [1,8] naphthyridin-6 (2jH)-one, m.pc 241-243*C; 7-(3-Chlorophenyl)-3,4,5,7-tetrahydro-oxepino[3,2-c] [1,8]naphthyridin-6(2^)-one, m.p. 151-153*C; 7-(3-Methoxyphenyl)-3,4,5,7-tetrahydro-oxepi no[3,2-c] [1,8] naphthyridin-6(2JO-one, m.p. 223-224.5*C; and 20 7-(3-Hydroxyphenyl)-3,4,5,7-tetrahydro-oxepino[3,2-c] [1,8] naphthyridin-6(2JO-one, m.p. >260*C PREPARATIVE EXAMPLES PREPARATIVE EXAMPLE 1 3-(2-Hydroxyethyl)-4-hydroxy-1-phenyl- 1,8-naphthyridin-2(1H)one To a solution of 6.8 g. of methyl 2-phenyl-amino-3-pyridine carboxylate in 60 ml. of gamma-butyro-lactone there was added, under nitrogen, 13.4 g. of potassium tertiary butoxide. The reaction mixture was heated and stirred for one hour at 95*C, poured on ice and stirred overnight. The mixture was extracted with ether, the aqueous layer acidified with acetic acid to pH 4.5 and the product was collected by filtration. Re-crystallization from chloroform, acetone, isopropanol yielded the product of this example as a colorless solid m.p. 235-236'C.

According to this procedure, or an art-recognized modification thereof, any of the 2-hydroxy-ethyl side-chain materials used as starting materials in the reactions described in Examples 1-8 may be prepared.

PREPARATIVE EXAMPLE 2 Methyl-2-phenylamino-3-pyrazine carboxylate (A) Methyl 2-bromo-3-pyrazine carboxylate: To a stirred mixture of 12.7 g. of methyl 2-amino pyrazine carboxylate and 47 ml. of 48% hydrobromic acid there was added, dropwise, 12.6 ml. of bromine keeping the temperature at 0*. A solution of 14.4 g. of sodium nitrite in 60 ml. of water was then added, drop-wise, at 0* and the reaction mixture stirred for 15 minutes. The reaction mixture was basified to pH 8 with sodium bicarbonate and extracted with ethyl acetate and again with chloroform. The organic layers were dried over magnesium sulfate, filtered and concentrated to a yellow oil. Recrystallization from ether-hexane yielded the product, m.p. 43-45*C.

(B) Methyl 2-phenylamino-3-pyrazine carboxylate: A mixture of 9.5 g. of methyl 2-bromo-3-pyrazine carboxylate, 8.2 g. of aniline, 0.5 g. of p-toluene sulfonic acid and 100 ml. of water was stirred and refluxed for two hours. The reaction mixture was poured on ice, extracted with ethyl acetate, the organic extracts were dried and concentrated to yield an oil. The crude residue was eluted on a silica gel column with ethyl acetate-hexane (1:2) yielding the product of this example as a yellow solid, m.p. 72-75*C.

PREPARATIVB EXAMPLE 3 4-Hydroxy-3-(3-hydroxypropyl)-1-(4-methoxyphenyl)-1,8-naphthyridin-2(1H)-one A mixture of delta-valerolactone (120 ml.), 5 ethyl 2-(4-methoxyphenylamino)nicotinate (12 g.) and potassium ^-butoxide (24 g.) was stirred and heated in an atmosphere of nitrogen to 100*C for 2 hrs. After cooling, the mixture was poured into 1000 ml. of 5% KOH solution and stirred overnight. The aqueous solution was 10 extracted with ether (2 x 250 ml.) which was discarded. The aqueous solution was then acidified to pH 4.5 with conc. HC1. The product was filtered off, washed with water, dried in air and recrystallized from CHC13/isopropanol to yield the desired product, m.p. 229-231*C.

According to this procedure, or an art- recognized modification thereof, any of the 3-hydroxy-propyl side-chain materials used as starting materials in the reactions described in Examples 1-8 may be prepared.

PREPARATIVE EXAMPLE 4 20 1-(3,4-Dichlorophenyl)-4-hydroxy-3-(2-hydroxypropyl)- 1,8-naphthyridin-2(1H)-one A stirred mixture of gamma-valerolactone i40 g.), ethyl 2-(3,4-dichlorophenylamino)-nicotinate (20 g.) and potassium ^-butoxide (30 g.) was warmed in an 25 atmosphere of nitrogen to 110*C and kept there for 5 hr. After cooling somewhat the product was poured into 1000 ml. of 5% KOH solution and was allowed to stir overnight. The basic solution was extracted with ether 4 (2 x 500 ml.) and the aqueous solution was acidified to pH 5 with conc. HC1. The solid was filtered off, washed with water, dried in air then recrystallized from methanol/charcoal to yield the desired product, m.p. 232-234'C.

This procedure or an art-recognized modified-tion thereof may be used to prepare any of the 2-hydroxy-propyl side-chain starting materials for use in Examples 1-8.

PREPARATIVE EXAMPLE 5 4-Hydroxy-3-(2-hydroxyhexyl)-1-phenyl-1,8-naphthyridin-2(1H)-one A mixture of methyl 2-phenylaminonicotinate (5 g.)f gamma-octanoic lactone (10 g.) and potassium -10 butoxide (7.5 g.) was stirred in a nitrogen atmosphere and heated to 95*C where it was held for 6 hrs. After cooling, the mixture was poured into 5% NaOH (200 ml.) and stirred overnight. Acidification to pH 4.6 yielded an oil, which was extracted with ether, washed with 15 water, dried (Na2SO^), filtered, and evaporated to a small volume. Rexane was added until turbidity was noticed, and the mixture was allowed to stand for about 5 hrs. The solid was filtered off and recrystallized from CH2Cl2/isopropanol/isopropyl ether to produce the desired 20 product, m.p. 184-186*C.

This process, or an art-recognized modification thereof may be used to prepare any of the 2-hydroxyhexyl side-chain starting materials for use in Examples 1-8. In general, by following the procedures 25 described in Preparative Examples 1, 4, 5 or 6, or an art-recognized modification thereof, using lactones with desired substituents, other intermediates, II (B ■ O), useful for conversion to the products of the invention according to one of the methods described in Examples 1-8 30 and 10 may be prepared.

PREPARATIVE1EXAMPLE 6 4-Hydroxy-3-(4-hydroxybutyl)-1-phenyl-1,8-naphthyridin-2(lH)-one A mixture of methyl 2-phenylamino-nicotinate (100 g.)» epsilon-caprolactone (1000 g.) and potassium t-butoxide (200 g.) was stirred at room temperature, in a nitrogen atmosphere, for^hr. It was heated at 45*C for 1 hr. then at 85"C for 2 hrs. and finally at 105*C for 3 hr.

The hot mixture was poured carefully into 8L of 5% KOH solution and was stirred overnight.

The mixture was extracted with 2L of ether and the aqueous phase was retained. It was extracted again with a fresh 2L of ether. The clear aqueous phase was adjusted to pH 4.5 with conc. HC1 to yield a white solid which was filtered off, washed with water and dried to yield 4-hydroxy-3-(4-hydroxybutyl)-1-phenyl-1,8-naphthyridin-2( IJ^-one, m.p. 205.5-206*0 (from isopropanol).

By substituting the relevant ester and lactone in this preparative example intermediates to many other compounds of the invention may bo prepared.

PREPARATIVE EXAMPLE 7 4-Hydroxy-3-(4-methanesulfonyloxybutyl)-1-pheny1-1,8-naphthyridin-2(lH)-one 4-Hydroxy-3-(4-hydroxybutyl)-1-phenyl-1,8-naphthyridin-2( IjO-one (10 g.) was dissolved, with stirring, in Eaton's Reagent (10% P20s *n methanesulfonic acid; 50 ml.) under a nitrogen atmosphere. The solution was heated to 55*C where it was held for 3hr. It was then cooled and poured into a water/ice mixture. After stirring for several hours, the aqueous mixture was extracted (3x) with ethyl acetate (250 ml. each). The organic extract was separated, dried (Na2S04), filtered and evaporated. The residue was stirred with a small volume of cold isopropanol and filtered to yield a brown solid, the mono-mesylate, which was used without further purification in Example 7.

PREPARATIVE EXAMPLE 8 2-(2-Chloro-3-nicotinoyl)-gamma-butyrolactone A 1M solution of lithium bis(trimethylsilyl)-amide (260 ml.; in hexane) was cooled to below -60*C in a nitrogen atmosphere. To this was added a solution of gamma-butyrolactone (25.8 g.) in tetrahydrofuran (40 ml.) keeping the temperature below -60*C. The mixture was stirred for 1 hr., then to it was added a solution of ethyl 2-chloro-nicotinate (37.2 g.) in tetrahydrofuran (60 ml.) keeping the reaction temperature below -60"C. After stirring for 2 hrs., the reaction mixture was allowed to warm to room temperature and it was kept there overnight. Most of the solvent was removed then 500 g. of ice was added to the residue. The aqueous layer was adjusted to pH 5 and was then extracted with methylene chloride (3 X 500 ml.). The dried methylene chloride extract was evaporated to an oil which was purified by preparative high pressure liquid chromatography separation (Whatman Magnum 40 column; Partisil 40, 0DS-3; CH3CN(25): H20(75): CH3C02H(1)) to yield the desired product, m.p. 50-52#C.

PREPARATIVE EXAMPLE 9 4-Hydroxy-3-(2-hydroxyethyl)-1-(3-nitrophenyl)-1,8-naphthyridin-2(1H)-one A mixture of 2-(2-chloro-3-nicotinoyl)-gamma-butyrolactone (Preparative Example 8) (3 g.) and m-nitroaniline (3.67 g.) in methanol (50 ml.) was stirred in a nitrogen atmosphere and heated to an oil bath temperature of 130*C. The methanol was allowed to distil off. After lV^-2 hr., the mixture was allowed to cool.

To the product was added 10% potassium hydroxide solution (200 ml.) and the mixture was stirred overnight. After adjusting the pH to 5.5, the solid product was filtered off, washed with water, dried, and recrystallized from 5 isopropanol to yield the desired product, m.p. 244- 245*C. Conversion of this material to compounds of the invention may be accomplished by utilizing the procedures described in the Examples.

Claims (24)

1. . A compound having the structural formula I w ✓ N. (CR9R10)n"V wherein: A is or C-B A' 10 15 B is independently oxygen or sulfur; R^-R® may be the same or different and are hydrogen or alkyl having from 1 to 6 carbon atoms or two adjacent R^-R® substituents may be combined to form an additional carbon to carbon bond; 1 and m may be the same or different and are 0 or 1; -59a- the ring labeled, Q, may optionally contain up to two additional double bonds; n is 0, 1 or 2; W and X may be the same or different and are hydrogen, hydroxy, alkyl having from 1 to 6 carbon atoms, halogen, nitro, alkoxy having from 1 to 6 carbon atoms, tri-fluoromethyl, cyano, cycloalkyl having from 3 to 7 carbon atoms, alkenyloxy having from 3 to 6 carbon atoms, alkynyloxy having from 3 to 6 carbon atoms, S(0)p-Ra [wherein p is 0, 1 or 2 and Ra is alkyl having from 1 to 6 carbon atoms] , NHS02Ra [wherein Ra is defined herein], NHSO2CF3, NHCOCF3, S02NH2, COR^[wherein Rb is OH, NH2 or ORa (wherein Ra is defined herein)], 0-D-C0Rb [wherein D is alkylene having from 1 to 4 carbon atoms and Rb is defined herein], or NHCORc [wherein Rc is hydrogen, alkyl having from 1 to 6 carbon atoms, alkoxy having from 1 to 6 carbon atoms, COR^ (wherein Rd is hydroxy or alkoxy having from 1 to 6 carbon atoms) or NHRe (wherein Re is hydrogen or alkyl having from 1 to 6 carbon atoms)], or phenoxy [wherein the benzene ring may be substituted with any of the other substituents W and X]; Y and Z may be the same or different and are CH or N; V is phenyl, naphthyl, indenyl, indanyl, pyridyl, pyrimidinyl, thienyl, furyl or thiazolyl, any of which may be substituted with W and X as defined herein; and q 1 n R and R u are independently hydrogen or alky] having from 1 to 6 carbon atoms.

2. The compounds defined in claim 1 wherein n is 0.

3. The compounds defined in claim 2 wherein Y is CH.

4. The compounds defined in claim 3 having the structural formula:

5. The compounds defined in claim 4 wherein Z is N.

6. The compounds defined in claim 5 wherein 1 and m are 0,

7. The compounds defined in claim 5 wherein 1 and m are 1»

8. The compounds defined in claim 6 or 7 wherein 6 is oxygen.

9. The compounds defined in claim 8 wherein V is - 61 -

10. The compounds defined in claim 9 having the structural formula: v « x

11. The compounds defined in claim 9 having the structural formula:

12. The compounds defined in claim 10 or 11 wherein R1-R® are hydrogen or methyl.

13. The compounds defined in claim 12 wherein zero or one of R^-R® is methyl and the rest are hydrogen. - 62

14. „ The compounds defined in claim 6 having the structural formula:

15. = The compounds defined in claim 6 having the structural formula:

16. The compounds defined in claim 13 or 15 wherein W is 3~ehloro and X is hydrogen, chlorine or fluorine.

17. The compounds defined iji claim 13 or 15 wherein W is 3-methoxy and X is hydrogen or fluorine.

18. The compounds defined in claim 13 or 15 wherein W and X are both hydrogen.

19. The compounds defined in claim 1 having the names: 3,5-dihydro-5-phenyl-furo[3,2-c][1,8] naphthyridin-4[2H] -one; 6-phenyl-2,3,4,6-tetrahydro-pyrano[3,2-c][1,8]-naphthyridin-5-one; 2-methy1-3,5-dihydro-5-phenyl-furo[3,2-c][1,8]-naphthyridin-4 [2JB] -one; 3,9-dihydro-9-phenyl-furo[2,3-b] [1 ,8] naphthyridin-4 (2H_]-one; 3,9-dihydro-9-(p-methylphenyl)-furo[2,3-b][1,8]naphthyridin-4 [2Hj-one; 3,9-dihydro-2-methyl-9-phenyl-furo[2,3-b][1,8]naphthy-ridin-4 [2jy-one; 3,5-dihydro-5-(p-methylphenyl)-furo[3,2-c][1,8]naphthy-::din-4 [2H]-or.e; 3,5-dihydro-5-(p-fluorophenyl)-furo[3,2-c][1,8]naphthyridin-4 [2H]-one; 3,5-dihydro-5-(m-methoxyphenyl)-furo[3,2-c][1,8]naphthyridin-4 [2jJj -one; 3,5-dihydro-5-(m-methylthiophenyl)-furo[3,2-c][1,8]-naphthyridin-4 [2jJ]-one; 3,9-dihydro-9-(p-fluorophenyl)-furo[2,3-b][1,8]naphthyridin-4 [2HJ -one; 3,9-dihydro-9-(m-methoxyphenyl)-furo[2,3-b][1,8]naphthyridin-4 [2HJ -one; - 64 - 3,9-dihydro-9-(m-methylthiophenyl)-furo[3,2-c][1*8]-naphthyridin-4 [2H_] -one; 3 ,5-dihydro-5-(3,4-dichlorophenyl)-furo [3 ,2-c][1,8]-naphthyridin-4[2H]-one; 3,5-dihydro-5-(3,4-dichlorophenyl)-2-methy1-furo 5 [3 ,2-c] [ 1 ,8] -naphthyridin-4 [2H_]-one; 3,5-dihydro-5-(4-chlorophenyl)-furo[3,2-c][1,8]-naphthyridin-4 [2_H]-one; 3,5-dihydro-5-(3-chlorophenyl)-furo[3,2-c][1,8]- * naphthyridin-4 [2H_]-one; 10 3,5-dihydro-5-(3-chlorophenyl)-2-methy1-furo[3,2-c][1 ,8]- naphthyridin-4 [2Hj-one; 3 ,5-dihydro-5- ( 4-fluorophenyl )-2-methy-f uro [3 ,2-c] [1,8]-naphthyridin-4[2^]-one; 3,5-dihydro-5-(3-methoxyphenyl)-2-methyl-furo 15 [3 ,2-c] [1,8] - naphthyridin-4 [2HJ - one; 3,5-dihydro-5-(3 ,5-dichlorophenyl)-furo[3,2-c][1,8] -naphthyridin-4[2H]-one; 3,5-dihydro-5-(3 ,5-dichlorophenyl)-2-methyl-furo [3,2-c] [1,8]-naphthyridin-4[2Hj-one; 20 3,5-dihydro-5-phenyl-2,2-dimethyl-furo[3,2-c][1 ,8]- naphthyridin-4 [2

20. A pharmaceutical composition which comprises a compound having structural formula I as defined in claim 1, in combination with a pharmaceutically acceptable carrier.

21. A process for the preparation of a compound of formula I as defined in claim X which is characterized by: - 67 J- a) treating a compound of the general formula 'IlVcR3*4! CR5R611[ CR7R8]m-OH (CR9R10)n-V II in which l,m,n, V,W,X,Y,Z, and R^-R^O are as defined with respect to formula I, with a dehydrating agent under anhydrous conditions to produce a compound of formula I in which A represents the grouping A" and both Bs are oxygen; b) treating a compound having the general formula R1R2CR3R4[ CR5R6]-OH c (CR9R10) -V n 10 in which l,n, V,W,X, Y, Z,r1-r6, r9 and R10 are as defined above, with a strong aqueous acid solution to produce a compound of formula I in which A represents the grouping A1 wherein m is zero and both Bs are oxygen; - 68 - c) cyclising a compound of the general formula OH in which Lg is a leaving group, l,m,n, V,W,X,Y,Z and r1_r10 are as defined with respect to formula I, to pro-5 duce a compound of formula I, in which the grouping A is A1 and both Bs are oxygen. i d) treating a compound of general formula II as defined in process a) above, under cyclising and thiating conditions so as to produce a compound of formula I or 1Q mixture thereof in which one or both Bs are sulfur and, if desired, separating a aompound of formula I from a mixture so produced; e) treating a compound having the general formula - 69 - in which l,n, V,W,X,Y,Z, R^-R^, R9 and R10 are as defined above with respect to formula I under thiating conditions so as to produce a compound of formula 1 in which the grouping A is A'wherein m is zero, B atom in ring Q is oxygen and the other B atom is sulphur. f) subjecting a compound having the general formula in which l,n, V,W,X,Y,Z, R^-R6, R9 and RlO are as defined above with respect to formula I, to intramolecular rearrangement, so as to produce a compound of formula I as defined above in which the. grouping A is A' , m is zero and both Bs are oxygen, g) subjecting a compound of the general formula I in which one of the B atoms is oxygen and the other is sulphur, to intramolecular rearrangement whereby the grouping A* or A" is converted respectively to the grouping A" or A' such that a cyclic oxygen atom or sulphur atom becomes a doubly bonded oxygen atom or•sulphur atom and the doubly bonded oxygen atom or sulphur atom becomes the ring oxygen atom or sulphur atom; - 70 - and thereafter, if desired, transforming a compound of formula I so obtained by a process a) , b), c), d) , e) , f) or g) into another compound of formula I.

22. The use of a compound of formula I as defined in 5 claim I in the treatment in mammals of allergic reactions,or inflammation, or peptic ulcers.

23. A process for the preparation of a compound of formula I as defined in claim 1, substantially as hereinbefore described by way of Example.

24. A compound of formula I as defined in claim 1, whenever prepared by a process as claimed in claim 21 or claim 23. Dated this 30th day of May 1984. BY: TOMKINS & CO., Applicants' Agents, (Signed) 5 Dartmouth Road, DUBLIN 6.