IE913604A1 - 1'-aminospiro[isoquinoline-4(1h),3'-pyrrolidine]-1,2',3,5'¹(2h)-tetrones and analogs thereof useful as aldose reductase¹inhibitors - Google Patents

Abstract

This invention relates to alkylidene analogs of r-aminospiro[isoquinoline-4(lH), 3’- pyrrolidine]-l,2’,3,5’(2H)-tetrones (I), to processes for their preparation, to methods for using the compounds, and to pharmaceutical preparations thereof. The compounds have pharmaceutical properties which render them beneficial for the prevention or treatment of diabetes mellitus associated complications.

Description

1'-AMINOSPIRO[ISOQUINOLINE-4(1H),3'-PYRROLIDINE]1,2',3,5'(2H)-TETRONES AND ANALOGS THEREOF USEFUL AS ALDOSE REDUCTASE INHIBITORS 5 This invention relates to r-aminospiro[isoquinoline-4(lH),3'-pyrrolidine]-l,2',3,5'(2H)tetrones and their pharmaceutically acceptable salts thereof, to processes for their preparation, to methods for using the compounds, and to pharmaceutical preparations thereof. The compounds have pharmaceutical properties which render them beneficial for the prevention or treatment of complications associated with diabetes mellitus.

The use of insulin and/or oral hypoglycemic agents in the treatment of diabetes mellitus has prolonged the life of many of these patients. However, their use has not had a demonstrable impact on the development of diabetic complications such as neuropathy, nephropathy, retinopathy, cataracts and vascular disease which accompany the underlying metabolic disorder. There is little question that chronic hyperglycemia plays a major role in the genesis of these complications, and 'hat complete normalization of blood glucose woiild likely prevent most if not all complications. For a number of reasons, though, chronic normalization of blood glucose has not been achieved with the currendy available therapies.

The long-term complications of diabetes develop in tissues where glucose uptake is independent of insulin. In these tissues, which include the lens, retina, kidney and peripheral nerves, the systemic hyperglycemia of diabetes is rapidly transposed into high tissular concentrations of glucose. In all of these tissues this excess glucose is rapidly metabolized by the sorbitol pathway. The intense diabetes-induced flux of glucose through this pathway appears to initiate a cascade of biochemical alterations which slowly progress to cell dysfunction and structural damage. Aldose reductase, the key enzyme in the sorbitol pathway, reduces glucose to sorbitol at the expense of the cofactor NADPH. In animal models of diabetes, compounds which inhibit aldose reductase have been shown to prevent the biochemical, functional and morphological changes induced by hyperglycemia. Early studies by J. H. Kinoshita and collaborators implicated aldose reductase in the etiology of diabetic cataracts. More recent studies have provided compelling evidence that aldose reductase also plays a significant role in the initiation of diabetic AHP-9693 j nephropathy, retinopathy and neuropathy (cf McCaleb et al, J. Diab. Comp., 2, 16,1989; Robison et al, Invest. Ophthalmol. Vis. Sci., 30,, 2285, 1989; Notvest and Inserra, Diabetes, 36, 500, 1987.

Prior,An The closest prior art is Malamas U.S. Patent 4,927,831, May 22, 1990, which discloses the spiro-isoquinoline-pyrrolidine tetrones of formula (r1 is hydrogen or fluorine) useful as aldose reductase inhibitors for treating complications of diabetes and galactosemia.

Summary of Invention 15 The r-aminospiro[isoquinoline-4(lH),3'-pynOlidine]-l,2’,3,5'(2H)-tetrones of the present invention are represented by formula (I): wherein: R1 and R2 are independently hydrogen, alkyl containing 1 to 6 carbon atoms, halogen, lower alkoxy containing 1 to 6 carbon atoms, trifluoromethyl, nitro, aryl or aryl (lower alkyl) oxy wherein aryl contains 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms; AHP-9693 R3 is lower alkyl containing 1 to 6 carbon atoms, aryl, aryl (lower alkyl) or dihalogen substituted aryl (lower alkyl) wherein aryl contains 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms; R4 and R5 are independently hydrogen, alkyl containing 1 to 6 carbon atoms, aryl or aryl 5 (lower alkyl) wherein aryl contains 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms, alkonoyl of 1 to 5 carbon atoms, carboalkoxy, alkylsulfoxy, arylsulfoxy, alkylsulfonyl, tnf luoromethylsulfonyl, arylsulfonyl or R and R are joined to form a heterocyclic ring or 5 to 7 ring atoms including the nitrogen atom to which they are attached and pharmaceutically acceptable salts thereof when 4 5 R and R are hydrogen, alkyl or aryl.

A more preferred group of compounds of the present invention is represented by formula I wherein R^ and R are hydrogen or halogen, R is a dihalogen ,, substituted benzyl, R and R are hydrogen, alkanoyl of 2 to 5 carbon atoms , carboalkoxy or trif1uoromethanesulfonyl.

The most preferred compounds of the present invention are set forth below: 0 r-amino-2-[(4-bromo-2-fluorophenyl)methyl]spiro[isoquinoline-4(lH),3'-pyrrolidine]l,2’,3,5'(2H)-tetrone; r-amino-2-[(4-bromo-2-fluorophenyl)methyl]-6-fluorospiro[isoquinoline-4(lH), 3'pyrrolidine]-1,2',3,5'(2H)-tetrone; N-[2-[(4-bromo-2-fluorophenyl)methyl]-2,3-dihydro-l,2',3,5'-tetraoxospiro[isoquinoline2 5 4(lH),3'-pyrrolidin]-r-yl]iminodicarbonic acid dimethyl ester, AHP-9693 N-[2-[(4-bromo-2-fluorophenyl)methyl]-2,3-dihydro-l,2',3,5'-tetraoxospiro[isoquinoline4(lH),3'-pyTTolidin]-r-yl]acetamide; and N-[2-[(4-bromo-2-fluorophenyl)methyl]-2,3-dihydro-l,2',3,5'-tetraoxospiro[isoquinoline4(lH),3'-pyrrolidin]-1 ’-yl]-1,1,1 -trifluoromethanesulfonamide.

The compounds of formula (I) all possess at least one asymmetric carbon atom, namely the spiro carbon atom at position 3' of the pyrrolidine ring. The compounds of formula (I) therefore exist, and may be isolated, in two or more stereoisomeric forms. This invention encompasses the compounds of formula (I) in racemic form or in any optically active form.

The r-aminospiro[isoquinoline-4(lH),3'-pyrrolidine]-l,2',3,5'(2H)-tetrones can be prepared by the processes described hereinafter.

A method is provided for preventing or relieving diabetes mellitus associated complications in a diabetic mammal by administering to said mammal a prophylactic or alleviating amount of the compounds of formula (I). Such complications include neuropathy, nephropathy, retinopathy, keratopathy, diabetic uveitis, cataracts and limited joint mobility.

The compounds of formula (I), when admixed with a pharmaceutically acceptable carrier, form a pharmaceutical composition which can be used according to the preceding method.

The r-aminospiro[isoquinoline-4(lH),3'-pyrrolidine]-l,2'3,5'(2H)-tetrones of this invention may be administered to mammals, for example, man, cattle, or rabbits, either alone or in dosage forms, i.e., capsules or tablets, combined with pharmacologically acceptable excipients.

The compounds of this invention may be given orally. However, the method of administering the present active ingredients of this invention is not to be construed as limited to a particular mode of administration. For example, the compounds may be administered topically directly to the eye in the form of drops of sterile, buffered ophthalmic solutions, preferably of pH 7.2-7.6. Also, they may be administered orally in solid form containing such excipients as starch, milk sugar, certain types of clay and so forth. They may also be administered orally in the form of solutions or they may be injected parenterally. For parenteral administration, they may be used in the form of a sterile solution, preferably of pH 7.2-7.6, containing a pharmaceutically acceptable buffer.

AHP-9693 The dosage of the r-aminospiro[isoquinoline-4(lH),3’-pyrrolidine]-l,2',3,5’(2H)tetrones will vary with the form of administration and the particular compound chosen. Furthermore, it will vary with the particular host under treatment. Generally, treatment is initiated with small dosages substantially less than the optimal dose of the compound. Thereafter, the dosage is increased by small increments until efficacy is obtained. In general, the compounds of this invention are most desirably administered at a concentration level that will generally afford effective results without causing any harmful or deleterious side effects. For topical administration, a 0.05-1.0% solution may be administered dropwise in the eye. The frequency of instillation varies with the subject under treatment from a drop every two or three days to once daily. For oral or parenteral administration a preferred level of dosage ranges from about 1.0 mg to about 10.0 mg per kilo of body weight per day, although aforementioned variations will occur. However, a dosage level that is in the range of from about 1.0 mg to about 10.0 mg per kilo of body weight per day is most satisfactory.

Unit dosage forms such as capsules, tablets, pills and the like may contain from about 5.0 mg to about 25.0 mg of the active ingredients of this invention with a pharmaceutical carrier. Thus, for oral administration, capsules can contain from between about 5.0 mg to about 25.0 mg of the active ingredients of this invention with or without a pharmaceutical diluent. Tablets, either effervescent or noneffervescent, can contain between about 5.0 to 25.0 mg of the active ingredients of this invention together with conventional pharmaceutical carriers. Thus tablets, which may be coated and either effervescent or noneffervescent, may be prepared according to the known art. Inert diluents or carriers, for example, magnesium carbonate or lactose, can be used together with conventional disintegrating agents for example, magnesium stearate.

The r-aminospiro[isoquinoline-4(lH),3'-pyrrolidine]-l,2'3,5,(2H)-tetrones also can be used in combination with insulin or oral hypoglycemic agents to produce a beneficial effect in the treatment of diabetes mellitus. In this instance, commercially available insulin preparations or oral hypoglycemic agents, exemplified by acetohexamide, chloipropamide, tolazamide, tolbutamide and phenformin, are suitable. The compounds hereof can be administered sequentially or simultaneously with insulin or the oral hypoglycemic agent. Suitable methods of administration, compositions and doses of the insulin preparation or oral hypoglycemic agent are described in medical textbooks; for instance, Physicians' Desk Reference, 42 ed., Medical Economics Co., Oradell, N.J., U.S.A., 1988.

AHP-9693 The aldose reductase inhibiting property of the compounds of this invention and the utilization of the compounds in preventing, diminishing and alleviating diabetic complications are demonstrable in experiments using galactosemic rats, see Dvomik etal., Science, 182, 1146 (1973). Such experiments are exemplified hereinbelow after the listing of the following general comments pertaining to these experiments: (a) Four or more groups of six male rats, 50-70 g, Sprague-Dawley strain, were used. The first group, the control group, was fed a mixture of laboratory chow (rodent Laboratory Chow, Purina) and glucose at 20% (w/w %) concentration. An untreated galactosemic group was fed a similar diet in which galactose was substituted for glucose. The third group was fed a diet prepared by mixing a given amount of the test compound with the galactose containing diet. The concentration of galactose in the diet of the treated groups was the same as that for the untreated galactosemic group. (b) After four days, the animals were killed by euthanization. Both the lens and sciatic nerve were removed, weighed and stored frozen for polyol determination. (c) The polyol determination was performed by a modification of the procedure of M.

Kraml and L. Cosyns, Clin. Biochem., 2, 373 (1969). Only two minor reagent changes were made: (a) the rinsing mixture was an aqueous 5% (w/v) trichloroacetic acid solution and (b) the stock solution was prepared by dissolving 25 mg of dulcitol in 100 mL of an aqueous trichloroacetic acid solution. [N.B.: For each experiment the average value found in the tissue from rats fed the glucose diet was subtracted from the individual values found in the corresponding tissue in galactose-fed rats to obtain the amount of polyol accumulated.] The aldose reductase inhibiting effects of the compounds of formula (I) were also tested by employing an in vitro testing procedure similar to that described by S. Hayman and J.H. Kinoshita, J. Biol. Chem., 240, 877 (1965). In the present case the procedure of Hayman and Kinoshita was modified in that the final chromatography step was omitted in the preparation of the enzyme from bovine lens.

The following tabulated results show that the l'-aminospiro[isoquinoline-4(lH),3'pynOlidine]-l,2',3,5'(2H)-tetrones of this invention show the property that they are active in vivo and diminish the accumulation of dulcitol in the lenses, sciatic nerves and diaphragm of rats fed galactose. The figures under L, N, and D represent the percentage decrease of dulcitol accumulation in the tissues of the lens, sciatic nerve, and diaphragm, respectively, for treated rats as compared to untreated rats.

AHP-9693 ALDOSE REDUCTASE INHIBITORS 5 % Lowering Galactitol Rl R4 R5 % Inhibition In Vitro 10*5M Dose mg/kg/day Accumulation In Vivo %(L) %(N) %(D) H H H 5 56 82 72 97 F H H 0 50.5 54 75 96 H H COCH3 20 57 25 73 90 H H SO2CF3 0 55 NS NS 66 H CO2CH3 CO2CH3 0 55 NS 50 82 (NS = not significant) This invention also provides a pharmaceutical composition comprising a compound of formula I as hereinbefore defined or a pharmaceutically acceptable salt thereof and a pharmaceutical carrier.

AHP-9693 -8This invention also provides processes for preparing the compounds of formula I or salts thereof. In particular the compounds of formula I may be prepared by one of the following: a) acylating a compound of formula R R NNH2 (XIII) wherein R and R are as defined above with a compound of formula (XIV) or an activated form thereof wherein CO~R is an ester function e.g alkyl 2 12 3 ester such as the methyl ester, and R , R and R are as defined above to give a corresponding compound of formula I and if desired where possible isolating as a salt, or b) acylating a compound of formula I wherein one of R and R5 is hydrogen, the other is selected from hydrogen, lower alkyl, aryl or ary1(1oweralkyl)- with an acylating agent (including sulfonylating and su1finy1 ating agents) containing the group R8CO- ,R8OCO- or R9S(O) AHP-9693 -98 9 · where R is alkyl and R is alkyl or aryl or, when'n is 9 1, R also represents trifluoromethyl, to give a . corresponding compound of formula I wherein R is hydrogen, alkyl, aryl or aryl (lowera1kyl) and R8 is alkanoyl, carboalkoxy, alkylsulfoxy, arylsulfoxy, alkylsulfonyl, arylsulfonyl or trifluoromethylsulfonyl . 4 5 or R and R are both alkoxycarbonyl , alkanoyl, alkylsulfoxy, arylsulfoxy, alkylsulfonyl, arylsulfonyl or trif1uoromethylsulfonyl.

With regard to process a) the acylation may be carried out using the carboxylic acid of formula XIV and a coupling agent such as a carbodiimide e.g dicyclohexylcarbodiimide . Alternatively the carboxylic acid group, may be in activated form e.g as an acid halide such as the chloride or bromide, or an anhydride such as a mixed anhydride. Processes for preparing compounds of formula III are described in Publication No GB 2224734 and EP Publication No 365324.

With regard to process b) examples of the acylating agent are acid halides and anhydrides e.g compounds of formula R8COhal, (R8CO)9O, R9S(O) hal, CR9SO )-0 and Z g Π z z haloformates such as Cl COOR .

Multiple acylation may be effected using a stoichiometric excess of acylating agent and more vigorous acylating conditions.

Preferred routes to compounds of the invention is showin in the process below:IE 913604 AHP-9693 -10The Process: The r-aminospiro[isoquinoline-4(lH),3'-pynOlidine]-l,2',3,5'(2H)-tetrones of the present invention were prepared by the following reaction scheme: O wherein R1 is halogen or hydrogen and R3 is a disubstituted aralkyl.

AHP-9693 -11Step a) Reacting either 2-bromobenzoic acid or 2-chlorobenzoic acid of formula (ΠΙ) wherein R1 is as defined above with dimethyl malonate and NaH in the presence of a catalytic amount of CuBr to produce the propanedioic acid dimethyl ester of formula (IV) wherein R1 is as defined above.

The 2-bromobenzoic acids or 2-chlorobenzoic acids of formula (EH) required for the present invention are commercially available compounds or can be prepared by known methods.

Step b) The propanedioic acid dimethyl ester of formula (IV) can be reacted with thionyl chloride under refluxing conditions to produce the corresponding acid chloride which upon treatment with Et3N in a conventional solvent which does not adversely influence the reaction, for example, tetrahydrofuran, can produce the compound of formula (V), wherein R1 is as defined above.

Step c) The compound of formula (V), wherein R1 is as defined above, is reacted with R3NH2 in the presence of ΕΐβΝ in a conventional solvent which does not adversely influence the reaction, for example, DMF, produces the compound of the formula (VI), wherein R1 and R3 are as defined above.

Step d) The compound of formula (VI), wherein R1 and R3 are as defined above, is reacted with an inorganic base such as potassium carbonate in a conventional solvent which does not adversely influence the reaction, for example, N,N-dimethy lformamide and subsequent addition of the tert-butyl bromoacetate produces the compound of formula (VII), wherein R1 and R3 are as defined above.

Step e) The compound of formula (VII), wherein R1 and R3 are as defined above, can be reacted with an organic acid such as trifluoroacetic acid in a conventional solvent which does not adversely influence the reaction, for example, methylene chloride, to produce the compound of formula (VIII), wherein R1 and R3 are as defined above.

AHP-9693 -12Step f) The compound of formula (VIII), wherein R1 and R3 are as defined above, can be reacted with a coupling agent such as l-(3-dimethylaminopropyl)-3-ethylcarbodiimide (DCC')/1hydroxybenzotriazole (HOBT) in a conventional solvent which does not adversely influence the reaction, for example, Ν,Ν-dimethylformamide, and subsequent addition of hydrazine and Et3N, produces the compound of formula (IX), wherein R1 and R3 are as defined above.

Step g) The compound of formula (IX), wherein R1 and R3 are as defined above can be reacted with methyl chloroformate in the presence of Et3N in a conventional solvent which does not adversely influence the reaction, for example, tetrahydrofuran, to produce the compound of formula (X), wherein R1 and R3 are as defined above.

Step h) The compound of formula (IX), wherein R1 and R3 are as defined above, can be reacted with acetic anhydride at 70’C, to produce the compound of formula (XI), wherein R1 and R3 are as defined above.

Step i) The compound of formula (IX), wherein R1 and R3 are as defined above, can be reacted with trifluoromethanesulfonic anhydride in the presence of Et3N in a conventional solvent which does not adversely influence the reaction, for example, methylene chloride, to produce the compound of formula (XII), wherein R1 and R3 are as defined above.

The following examples further illustrate this invention: EXAMPLE 1 l'-Amino-2-[(4-bromo-2-fiuorophenyI)methyl]spiro[isoquinoline-4(lH),3'pyrrolidine]-l,2',3,5'(2H)-tetrone Step a) (2-Carboxyphenyl)propanedioic Acid Dimethyl Ester To a rapidly stirred cold suspension (0°C) of 2-bromobenzoic acid (30.0 g, 149.32 mmol), cuprous bromide (2.14 g, 14.93 mmol) and dimethyl malonate (300 mL) was added NaH (80% in mineral oil, 10.75 g, 358.37 mmol) over a 30 minute period, while a stream of dry N2 was passed over the mixture. After the addition of the NaH had been completed, the mixture was stirred for 10 minutes at room temperature and 30 minutes at 70°C (external oil bath temperature). At this point, the suspension had turned to a solid mass, which was dissolved in H2O (1000 mL). The aqueous layer was extracted with diethyl ether (3 x 500 mL) and was acidified with HCl (2N). The mixture AHP-9693 -13was extracted with EtOAc and dried over MgSO4. Evaporation gave an off-white solid which was recrystallized from Et2O/hexane (after cooling to -20°C) to give a white solid (34.2 g, 90.9%, m.p. 119-120°C ).

IH NMR (DMSO-d6, 400 MHz): δ 3.67 [s, 6H, -CHfCO^CH^)?!. 5.72 [s, IH, CH(CO?CH3b1. 7.3 (d, J = 7.76 Hz, IH, Ar-H), 7.45 (dt, J = 7.66 Hz, 1.12 Hz, IH, Ar-H), 7.6 (dt, J = 7.66 Hz, 1.45 Hz, IH, Ar-H), 7.94 (dd, J = 7.8 Hz, 1.33 Hz, IH, Ar-H), 13.2 (s, IH, -CO2H) IR (KBr, cm*1): 3300-2700 (CO2H), 1750 (CO), 1730 (CO), 1680 (CO) MS (m/e): 252 (M+), 220 (M+-CH30H), 188 (M+-2 x CH3OH) Anal. Calcd.: C, 57.14; H, 4.80 Found: C, 57.05; H; 4.78.

The following compounds were prepared in substantially the same manner as that of Example 1, Step a): (2-Carboxy-6-fluorophenyI)propanedioic Acid Dimethyl Ester IH NMR (DMSO-d$, 400 MHz): δ 3.68 [s, 6H, (-CEbMebl, 5.79 [s, IH, Ar-£H(CO2Me)2], 7.12 (dd, J = 10.06 Hz, 2.61 Hz, IH, Ar-H), 7.33 (dt, J = 8.48 Hz, 2.64 Hz, IH, Ar-H), 8.03 (dd, 8.77 Hz, 6.17 Hz, IH, Ar-H) IR (KBr, cm-1): 3400-2700 (CO2H), 1730 (CO), 1680 (CO) MS (m/e): 270 (M+), 238 (M+-CH3OH), 210 (M+-CH3OH, -CO), 151 (M+-CH3OH, -CO, -CO2CH3) Anal. Calcd.: C, 53.34; H, 4.10 Found: C, 53.36; H, 3.93 m.p. 121.5-123.0°C. (2-Carboxy-6-chlorophenyI)propanedioic Acid Dimethyl Ester JH NMR (DMSO-d6, 200 MHz): δ 3.69 [s, 6H, (-CO2Me)2], 5.78 [s, IH, Ar-CH(CO2Me)2], 7.38 (d, J = 1.8 Hz, IH, Ar-H), 7.58 (dd, J = 7.8 Hz, 1.8 Hz, IH, Ar-H), 7.96 (d, J = 8.2 Hz, IH, Ar-H), 13.5 (br s, IH, -CO2H) AHP-9693 -14IR (KBr, cm'1): 3200-2700 (CO2H), 1760 (CO), 1740 (CO), 1690 (CO) MS (m/e): 286 (20 M+), 254 (64, M+-CH3OH), 222 (60, M+-2 x CH3OH) Anal. Calcd.: C, 50.28; H, 3.87 Found: C, 50.40; H, 3.87 m.p. 125-127°C. (2-Carboxy-6-bromophenyI)propanedioic Acid Dimethyl Ester !H NMR (DMSO-dg, 400 MHz): δ 3.68 [s, 6H, -iCOiCHibl. 5.74 (s, IH, Ar-CH-1. 7.5 (d, J = 2.02 Hz, IH, Ar-H), 7.70 (dd, J = 8.4 Hz, 1.98 Hz, IH, Ar-H), 7.87 (d, J = 8.41 Hz, IH, Aril) IR (KBr, cm-1): 3400-2300 (CO2H), 1745 (CO), 1720 (CO), 1695 (CO) MS (m/e): 330 (M+), 298 (M+-CH3OH) Anal. Calcd.: C, 43.53; H, 3.35 Found: C, 43.56; H, 3.23 m.p. 127-128°C.

Step b) 3-Methoxy-l-oxo-lH-2-benzopyran-4-carboxyIic Acid Methyl Ester A mixture of (2-carboxyphenyl)propanedioic acid dimethyl ester (10.0 g, 39.68 mmol) and SOCI2 (100 g) was refluxed for 2 hours. The volatiles were removed in vacuo and the crude product (acid chloride) was dissolved in THF (200 mL). Triethylamine (27.64 mL, 198.4 mmol) was added and the mixture was stirred for 30 minutes. The yellowish suspension was poured into HCl (IN, 1000 mL), extracted with EtOAc and the organic extracts were dried over MgSO4. Evaporation and crystallization from acetone/ether/hexane (after cooling to -20°C) gave a white solid (87.6 g, 94.4%, m.p. 129-130°C).

!H NMR (DMSO-dg, 400 ΜΗζ):δ 3.82, (s, 3H, -CCbMe). 4.03 (s, 3H, -QMe). 7.42 (t, J = 7.26 Hz, IH, Ar-H), 7.8 (t, J = 8.2 Hz, IH, Ar-H), 7.9 (d, J = 8.3 Hz, IH, Ar-H), 8.1 (d, J = 7.26 Hz, IH, Ar-H) IR (KBr, cm’1): 1740 (CO), 1685 (CO) MS (m/e): 234 (15, M+), 206 (38.5, M+-CO), 203 (12, M+-OMe) Anal. Calcd.: C, 61.59; H. 4.30 Found: C, 61.82; H, 4.29.

AHP-9693 -15The following compounds were prepared in substantially the same manner as that of Example 1, Step b): 6-Fluoro-3-methoxy-l-oxo-lH-2-benzopyran-4-carboxylic Acid Methyl Ester 1H NMK-(DMSO-d^, 400 MHz): δ 3.81 (s, 3H, -CCbCHa). 4.06 (s, 3H, -OCHv). 7.27 (dt, J = 8.3 Hz, 1H, Ar-H), 7.8 (dd, J = 11.83 Hz, 2.49 Hz, 1H, Ar-H), 8.16 (dd, J = 8.92 Hz, 6.2 Hz, 1H, Ar-H) IR (KBr, cm-1): 1750 (CO), 1685 (CO) MS (m/e): 252 (24, M+), 224 (54, M+-CO) Anal. Calcd.: C, 57.15; H, 3.60 Found: C, 57.19; H. 3.57 15 m.p. 142-143°C. 6-Chloro-3-methoxy-l-oxo-lH-2-benzopyran-4-carboxylic Acid Methyl Ester ]H NMR (DMSO-D6, 400 MHz): δ 3.81 (s, 3H, -CONCHO, 4.05 (s, 3H, -OCH3), 7.44 (dd, J = 20 8.56 Hz, 1.99 Hz, 1H, Ar-H), 8.06 (m, 2H, Ar-H) IR (KBr, cm'1): 1750 (CO), 1690 (CO) MS (m/e): 268 (34, M+), 240 (86, M+-CO) Anal. Calcd.: C, 53.65; H, 3.38 Found: C, 53.59; H, 3.35 m.p. 194-195°C. 6-Bromo-3-methoxy-l-oxo-lH-2-benzopyran-4-carboxyIic Acid Methyl Ester !H NMR (DMSO-d6, 400 MHz): δ 3.81 (s, 3H, -CO2CH3), 4.05 (s, 3H, -OCH2), 7.6 (dd, J = 8.38 Hz, 1.77 Hz, 1H, Ar-H), 8.0 (d, J = 8.39 Hz, 1H, Ar-H), 8.23 (d, J = 1.95 Hz, 1H, Ar-H) IR (KBr, cm-1): 1740 (CO), 1680 (CO) MS (m/e): 312 (17 M+), 284 (45, M+-CO) Anal. Calcd.: C, 46.03; H, 2.90 Found: C, 46.12; H, 2.62 m.p. 200-201’C.

AHP-9693 -16Step c) 2-[(4-Bromo-2-fluorophenyI)methyl]-l,2,3,4-tetrahydro-l,3-dioxo-4isoquino-Iinecarboxyiic Acid Methyl Ester To a solution of 3-methoxy-l-oxo-lH-2-benzopyran-4-carboxylic acid methyl ester (5.0 g, 21.37 mmol) in DMF (100 mL) were added 4-bromo-2-fluorobenzylamine (4.36 g, 21.37 mmol) and Et3N (5.96 mL, 42.74 mmol). The mixture was stirred at 80°C for 30 minutes, poured into H2O (1500 mL), acidified with HCl (2N) and extracted with EtOAc. The organic extracts were dried over MgSC>4. Evaporation and crystallization from acetone/hexane (after cooling to -20°C) gave a white solid (7.6 g, 87.7 %, m.p. 149-150°C). 1H NMR (DMSO-ύό, 400 MHz): δ [3.67 (s), 4.0 (s), 3H, -CQcMe. tautomeric], [5.06 (q), J = .4 Hz, 5.30 (s), 2H, -NCH?-. tautomeric], 5.4 (s), 1H, CH-CCbMe. tautomeric], 7.07-8.43 (m, 7H, Ar-H, tautomeric) IR (KBr, cm*1): 1670 (CO), 1605 (CO) MS (+ FAB): 406 (80, M++ H), 374 (40, M+ -OCH3) Anal. Calcd.: C, 53.22; H, 3.23; N, 3.45 Found: C, 53.19; H, 2.98; N, 3.40.

The following compounds were prepared in substantially the same manner as that of Example 1, Step c): 2-[(4-Bromo-2-fluorophenyl)methyI]-6-fluoro-l,2,3,4-tetrahydro-l,3-dioxo-4isoquinolinecarboxylic Acid Methyl Ester JH NMR (DMSO-d6, 400 MHz): δ 3.98 (s, 3H, -COoCH?). 5.27 (s, 2H, -N£H2-). 7.08 (t, J =7.95 Hz, 2H, Ar-H), 7.2 (m, 1H, Ar-H), 7.34 (m, 2H, Ar-H, -QH), 7.54 (m, 1H, Ar-H), 8.130 8.26 (m, 2H, Ar-H) IR (KBr, cm-1): 1680 (CO), 1660 (CO), 1610 (CO) MS (m/e): 423 (M+), 391 (M+-CH3OH) Anal. Calcd.: C, 50.97; H, 2.85; N, 3.30 Found: C, 50.86; H, 2.86; N, 3.33 m.p. 157-158°C.

AHP-9693 -176-Chloro-l,2,3,4-tetrahydro-2-inethyl-l,3-dioxo-4-isoquinolinecarboxyIic Acid Methyl Ester 1H NMR ](DMSO-d6, 200 MHz): δ [3.23 (s), 3.44 (s), tautomeric, 3H, -NCHri. [3.71 (s), 4.03 (s), tautomeric, 3H, -CCbCHri , 7.3-8.4 (tautomeric, Ar-H, -OH, 4H) IR (KBr, cm·1): 3440 (OH), 1680 (CO), 1600 (CO) MS (m/e): 267 (M+), 235 (M+ -OMe) Anal. Calcd.: C, 53.85; H, 3.77; N, 5.23 Found: C, 53.66; H, 3.63; N, 5.14 m.p. 166-167°C. 6-Bromo-l,2,3.4-tetrahydro-2-methyI-l,3-dioxo-4-isoquinoIinecarboxyIic Acid Methyl Ester 1H NMR (DMSO-d6, 400 MHz): 6 [3.2 (s), 3.42 (s), 3H, tautomeric, N-CHri. [3.7 (s), 4.01 (s), 3H, tautomeric, -CQ9CH3L [5.33 (s), 1H, tautomeric, Ar-£H-], [7.5 (dd), 7.8 (dd), tautomeric, 1H, Ar-H, [8.0 (d), 8.08 (d), tautomeric, 1H, Ar-H], [8.51 (d), 7.63 (d), tautomeric, 1H, Ar-H) IR (KBr, cm-1): 1665 (CO), 605 (CO) MS (m/e): 311 (M+) Anal. Calcd.: C, 46.18; H, 3.23; N, 4.49 25 Found: C, 45.83; H, 2.77; N, 4.38 m.p. 190-191°C.

Step d) 2-[(4-Bromo-2-fluorophenyl)methyI]-l,2,3,4-tetrahydro-4(methoxycarbonyl)-l,3-dioxo-4-isoquinoIineacetic Acid 1,1-DimethylethyI Ester To a suspension of 2-[(4-bromo-2-fluorophenyl)methyl]-1,2,3,4-tetrahydro-l,3-dioxo-4isoquinolinecarboxylic acid methyl ester (4.79 g, 11.58 mmol), K2CO3 (3.19 g, 23.16 mmol) in DMF (100 mL) was added tert-butyl bromoacetate (2.81 mL, 17.37 mmol). After stirring at 75°C for 1 hour, the mixture was poured into H2O, extracted with EtOAc and dried over MgSO4.

Evaporation and purification by flash chromatography (hexane/EtOAc 4/1) gave a clear oil (5.69 g, 94.5%).

AHP-9693 -18!H NMR (DMSO-d6, 400 MHz): δ 1.04 [s, 9H, -CfCHO?!. 3.53 s, 3H, -CCbCH-Q. 3.60 [dd, J = 17.7 Hz, 2H, -£H2CO2(CH3)3], 5.14 (s, 2H, NCH?-~). 7.17 (t, J = 8.25 Hz, IH, Ar-H), 7.36 (dd, J = 8.36 Hz, 1.75 Hz, IH, Ar-H), 7.6 (m, 3H, Ar-H), 7.77 (dt, J = 7.2 Hz, 1.27 Hz, IH, Ar-H), 8.19 (dd, J = 8.25 Hz, 1.54 Hz, IH, Ar-H) IR (CHC13, cm-1): 1720 (CO), 1675 (CO) MS (m/e): 520 (M + H)+, 464 [M+-C(CH3)3].

The following compounds were prepared in substantially the same manner as that of Example 1, Step d): 2-[(4-Bromo-2-fluorophenyl)methyl]-6-fluoro-l,2,3,4«tetrahydro-4(methoxycarbonyI)-l,3-dioxo-4-isoquinoIineacetic Acid 1,1-DimethylethyI Ester JH NMR (DMSO-de, 200 MHz): δ 1.10 (s, 9H, -CMe?). 3.55 (s, 3H, -CC>2CH3), 3.62 (d, J = 17.5 Hz, IH, -£H2CO2CMe3), 3.75 (d, J = 17.5 Hz, IH, -£H2CO2CMe3), 5.15 (s, 2H, NCH?-). 7.15 (t, J = 8.2 Hz, IH, Ar-H), 7.35 (d, J = 8.2 Hz, IH, Ar-H), 7.45-7.70 (m, 3H, ArH), 8.38 (dd, J = 8.16 Hz, 5.70 Hz, IH, Ar-H) IR (KBr, cm*1): 1750 (CO), 1720 (CO), 1675 (CO) MS (m/e): 538 (M + H)+, 481 (M+ + H-CMe3) Anal. Calcd.: C, 53.55; H, 4.12; N, 2.60 Found: C, 53.49; H, 4.00; N, 2.63. 6-Chloro-l,2,3,4-tetrahydro-4-(methoxycarbonyI)-2-methyl-l,3-d*<>xO'4isoquinolineacetic Acid 1,1-Dimethylethyl Ester IH NMR (DMSO-d6, 200 MHz): δ 1.06 (s, 9H, -CO2CMe3), 3.3 (s, 3H, -N£H3). 3.6 (s, 3H, 30 CO?CH3). 3.67 (q, J = 17.5 Hz, 2H, -CH^COaCMe^). 7.68 (dd, J = 9.0 Hz, 1.6 Hz, IH, ArH), 7.77 (d, J = 2.0 Hz, IH, Ar-H), 8.21 (d, J = 8.2 Hz, IH, Ar-H) IR (KBr, cm-1): 1740 (CO), 1720 (CO), 1680 (CO) MS (m/e): 381 (M+) Anal. Calcd.: C, 56.82; H, 5.28; N, 3.67 Found: C, 57.00; H, 5.41; N, 3.66 m.p. 135-136°C.

AHP-9693 -196-Bromo-I,2,3,4-tetrahydro-4-(methoxycarbonyl)-2-methyl-l,3-dioxo-4isoquinolineacetic Acid 1,1-Dimethylethyl Ester 1H NMR (DMSO-d6, 200 MHz): 5l.05rs.9H.-C(CHO?1.3.28 (s.3H.-NCH^).3.59(s.3H. CCbCHO. 3.58 (d, J = 17.03 Hz, 1H, -CH^CO?-). 3.67 (d, J = 17.03 Hz, 1H, -£H2CO2-), 7.81 (dd, J = 8.4 Hz, 1.85 Hz, 1H, Ar-H), 7.88 (d, J = 1.81 Hz, 1H, Ar-H), 8.08 (d, J = 8.4 Hz, 1H, Ar-H) IR (KBr, cm-1): 1740 (CO), 1710 (CO), 1670 (CO) MS (m/e): 425 (M+), 370 (M+ -C4H7), 352 (M+-C4H9O) Anal. Calcd.: AC, 50.72; H, 4.73; N, 3.29 Found: C, 50.47; H, 4.68; N, 3.12 m.p. 152-153°C.

Step e) 2-[(4-Bromo-2-fluorophenyI)methyI]-l,2,3»4,-tetrahydro-4(methoxycarbonyl)-l,3-dioxo-4-isoquino!ineacetic Acid A mixture of 2-[(4-bromo-2-fluorophenyl)methyl]-l,2,3,4-tetrahydro-420 (methoxycarbonyl)-l,3-dioxo-4-isoquinolineacetic acid 1,1-dimethylethyl ester (5.19 g, 9.81 mmol), CH2CI2 (100 mL) and CF3CO2H (20 mL) was stirred at room temperature for 5 hours. The volatiles were removed in vacuo and the residue was purified by flash chromatography on acid washed silica gel (5% H3PO4 in MeOH), to give a white solid (4.12 g, 90.5%, m.p. 139-140°C).

!H NMR (DMSO-d6, 400 MHz): 5 3.54 (s, 3H, CO?CH^). 3.64 (q, J = 17.67 Hz, 2H, CH2CO2H), 5.12 (q, J = 15.34 Hz, 2H, -N£H2-), 7.14 (t, J = 8.22 Hz, 1H, Ar-H), 7.3 (d, J = 8.3 Hz, 1H, Ar-H), 7.5-7.6 (m, 3H, Ar-H), 7.76 (d, J = 7.4 Hz, 1H, Ar-H), 8.16 ( d, J = 7.8 Hz, 1H, Ar-H), 12.35 (s, 1H, -CO2H) IR (KBr, cm-1): 3280 (OH), 3200-2700 (CO2H), 1750 (CO), 1720 (CO), 1675 (CO) MS (m/e): 463 (M+), 445 (M+-H, -OH) Anal. Calcd.: C, 51.28; H, 3.30; N, 2.99 Found: C, 51.26; H, 3.48; N, 2.95.

AHP-9693 -20The following compound was obtained in substantially the same manner as that of Example l, Stepe): 2-[(4-Bromo-2-fluorophenyI)methyI]-6-fluoro-l,2,3,4-tetrahydro-4-(methoxycarbonyl)-l,3-dioxo-4-isoquino!ineacetic Acid 1H NMR (DMSO-de, 400 MHz): 5 3.56 (s, 3H, -CO?CH3).3.6(d.J = 17.9 Hz, 1H, -CHoCCbH). 3.8 (d, J = 17.9 Hz, 1H, -CHr>CO?H). 5.1 (dd, J = 15.5 Hz, 2H, -NCH2-). 7.12 (s, J = 8.23 Hz, 1H, Ar-H), 7.31 (dd, J = 8.28 Hz, 1.68 Hz, 1H, Ar-H), 7.45 (dt, J = 8.56 Hz, 2.5 Hz, 1H, Ar-H), 7.54 (dd, J .= 9.77 Hz, 1.89 Hz, 1H, Ar-H), 7.64 (dd, J = 9.61 Hz, 2.46 Hz, 1H, Ar-H), 8.23 (dd, J = 8.79 Hz, 5.81 Hz, 1H, Ar-H), 12.67 (br s, 1H, -CO2H) IR (KBr, cm-1): 3400-2700 (CO2H), 1745 (CO), 1710 (CO), 1670 (CO) MS (m/e): 481 (M+), 405 (M+-CO2, -CH3OH) Anal. Calcd.: C, 49.81; H, 2.93; N, 2.90 Found: C, 49.94; H, 3.03; N, 2.84 m. p. 132-133.5°C. 6-ChIoro-1,2,3,4-tetrahy dro-4-(methoxycarbonyI)-2-methyl-l,3-dioxo-4isoquinolineacetic Acid 1H NMR (DMSO-d6, 200 MHz): δ 3.27 (s, 3H, -CH^). 3.59 (s, 3H, -CONCHO. 3.64 (q, J = 17.5 Hz, 2H, -£H2CO2H), 7.65 (dd, J = 8.6 Hz, 2.0 Hz, 1H, Ar-H), 7.78 (d, J = 2.0 Hz, IH, Ar-H), 8.18 (d, J = 8.0 Hz, 1H, Ar-H) IR (KBr, cm’1): 3440 (OH), 3200-2700 (CO2H), 1750 (CO), 1710 (CO), 1675 (CO) MS (m/e): 325 (M+) Anal. Calcd.: C, 51.63; H, 3.71; N, 4.30 Found: C, 51.73; H, 2.70; N, 4.28 m.p. 195-196°C. 6-Bromo-l,2,3,4-tetrahydro-4-(methoxycarbonyl)-2-methyl-l,3-dioxo-4isoquinoiineacetic Acid AHP-9693 -21JH NMR (DMSO-dg, 200 MHz): δ 3.26 (s, 3H, N-CHa). 3.53 (d, J = 17.2 Hz, IH, -CH?H). 3.58 (s, 3H, -CO2£H3), 3.74 (d, J = 17.2 Hz, IH, -CH?CO?H). 7.77 (dd, J = 8.2 Hz, 2.2 Hz, IH, Ar-H), 7.87 (d, J = 2.2 Hz, IH, Ar-H), 8.0 (d, J = 8.2 Hz, IH, Ar-H), 12.64 (s, IH, CO2H) IR (KBr, cm-1): 3450-2600 (CO#), 1735 (CO), 1700 (CO), 1660 (CO) MS (m/e): 369 (M+), 324 (M+-CO2H) Anal. Calcd.: C, 45.43; H, 3.27; N, 3.78 Found: C, 45.04; H, 3.16; N, 3.62 m.p. 194-195°C.

Step f) l'-Amino-2-[(4-bromo-2-fluorophenyl)methyl]spiro[isoquinoIine4(lH),3'-pyrrolidine]-l,2',3,5’(2H)-tetrone To a solution of 2-[(4-bromo-2-fluorophenyl)methyl]-l,2,3,4-tetrahydro-4(methoxycarbonyl)-l,3-dioxo-4-isoquinolineacetic acid (2.5 g, 5.39 mmol) in DMF (60 mL) were added l-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (DCC, 1.34 g, 7.0 mmol) and 1-hydroxybenzotriazole hydrate (HOBT, 1.09 g, 8.08 mmol). After stirring for 2 hours, anhydrous hydrazine (0.22 mL, 7.0 mmol) was added dropwise, followed by Et3N (1.5 mL, 10.77 mmol) addition. The mixture was stirred for 30 minutes, poured into H2O, neutralized with HCl (2N) and extracted with EtOAc. The organic extracts were dried over MgSO4. Evaporation and purification by flash chromatography (hexane/EtOAc 1:1) and subsequent crystallization from ether/hexane (after cooling to -20°C) gave a white solid (1.68 g, 70.0%, m.p. 95-97’C).

!H NMR (DMSO-dg, 400 MHz): δ 3.33 (d, J = 18.2 Hz, IH, -HCHCO-), 3.51 (d, J = 18.2 Hz, IH, -HCHCO-). 5.07 (s, 2H, -NCH?-). 5.23 (s, 2H, -NH?). 7.17 (t, J = 8.3 Hz, IH, Ar-H), 7.33 (dd, J = 8.3 Hz, 1.7 Hz, IH, Ar-H), 7.54 (m, 2H, Ar-H), 7.63 (t, J = 8.51 Hz, IH, Ar-H), 7.79 (dt, J = 8.7 Hz, 1.25 Hz, IH, Ar-H), 8.18 (dd, J = 7.7 Hz, 1.25 Hz, IH, Ar-H) IR (KBr cm-1): 3340 (NH), 1720 (C=O), 1670 (C=O) MS (m/e): 445(4, M+) Anal. Calcd.: C, 51.14; H, 2.94; N, 9.42 Found: C, 51.04; H, 2.94; N, 9.30.

AHP-9693 -22The following compound was prepared in substantially the same manner as that of Example l, Step f) l’-Amino-2-[(4-bromo-2-fluorophenyl)methyI]-6-fluorospiro[isoquinoline4(lH),3’-pyrroIidine]-l,2',3,5'(2H)-tetrone !H NMR (DMSO-d6, 400 MHz): δ 3.42 (q, J = 18.2 Hz, 2H, -CH^CO-l 5.05 (s, 2H, -NCH?-). .18 (s, 2H, -NH2), 7.15 (t, J = 8.3 Hz, IH, Ar-H), 7.33 (dd, J = 8.1 Hz, 1.66 Hz, IH, Ar-H), 7.49 (dt, J = 8.5 Hz, 2.29 Hz, IH, Ar-H), 7.55 (dd, J = 9.96 Hz, 1.87 Hz, IH, Ar-H), 7.6 (dd, J = 9.75 Hz, 2.49 Hz, IH, Ar-H), 8.24 (dd, J = 8.9 Hz, 5.8 Hz, IH, Ar-H) IR (KBr, cm-1): 3350 (NH), 3280 (NH), 1730 (C=O), 1710 (C=O), 1670 (C=O) MS (m/e): 463 (94 M+) Anal. Calcd.: C, 49.16; H, 2.61; N, 9.05 Found: C, 49.19; H, 2.66; N, 8.96 m. p. 232-234°C.

EXAMPLE 2 N-[2-[(4-Bromo-2-fluorophenyl)methyl]-2,3-dihydro-l,2’,3,5'-tetraoxospiro[isoquinoline-4(lH),3'-pyrroIidin]-l'-yI]iminodicarbonic Acid Dimethyl Ester To a cold (0°C) solution of l'-amino-2-[(4-bromo-2-fluorophenyl)methyl]spiro25 [isoquinoline-4(lH),3'-pyrrolidine]-l,2',3,5'(2H)-tetrone (2.0 g, 4.48 mmol) in THF (50 mL) was added Et3N (3.12 mL, 22.4 mmol) followed by dropwise addition of methyl chloroformate (1.04 mL, 13.44 mmol). After stirring for 30 minutes, the mixture was poured into H2O, acidified with HCl (2N) and extracted with EtOAc. The organic extracts were dried over MgSO4Evaporation and purification by flash chromatography on silica gel (hexane/EtOAc 2:1) gave a white solid (2.1 g, 83.3%, m.p. 214-216°C).

AHP-9693 -23JH NMR (DMSO-d2CH3),3.76 (d, J =18.9 Hz, 1H, -HCHCO-), 3.81 (d, J = 18.9 Hz, 1H, -HCH.CO-), 3.83 (s, 3H, -CO2CH3), 5.1 (s, 2H, -NQh-), 7.18 (t, J = 8.1 Hz, 1H, Ar-H). 7.34 (dd, J = 8.3 Hz, 1.87 Hz, 1H, Ar-H). 7.56 (m, 2H. Ar-H), 7.68 (t, J = 7.47 Hz, 1H, Ar-H), 7.86 (dt, J = 7.68 Hz, 1.45 Hz, 1H, Ar-H), 8.21 (dd, J = 7.88 Hz, 1.25 Hz, 1H, Ar-H) IR (KBr, cm-1): 1810 (C=O), 1745 (C=O), 1670 (C=O) MS (m/e): 561 (50, M+) Anal. Calcd.: C, 49.13; H, 3.05; N, 7.47 Found: C, 49.33; H, 3.22; N, 7.26.

EXAMPLE 3 15 N-[2-[(4-Bromo-2-fIuorophenyI)methyI]-2,3-dihydro-l,2’,3,5'-tetraoxospiro[isoquinoIine-4(lH),3’-pyrrolidin]-l'-yl]acetamide A mixture of l'-amino-2-[(4-bromo-2-fluorophenyl)methyl]spiro[isoquinoline-4(lH),3'20 pyrrolidine]-1,2',3,5'(2H)-tetrone (2.0 g, 4.48 mmol) and acetic anhydride (20 mL) was stirred at 70°C for 30 minutes. The volatiles were removed in vacuo and the residue was purified by flash chromatography on silica gel (hexane/EtOAc 1:1) to give a white solid (1.91 g, 87.3%, m.p. 219221 °C).

!H NMR (DMSO-de, 400 MHz): δ 1.98 (s, 3H, -COCH3), 3.5 (d, J = 18.9 Hz, 1H, -HCHCO-), 3.7 (d, J = 18.9 Hz, 1H, -HCHCO-), 5.09 (dd, J = 16.2 Hz, 2H, -CH2-N), 7.17 (t, J = 8.3 Hz, 1H, Ar-H), 7.35 (d, J = 7.9 Hz, 1H, Ar-H), 7.56 (m, 2H, Ar-H), 7.65 (t, J = 7.68 Hz, 1H, ArH), 7.84 (dt, J = 7.68 Hz, 1.25 Hz, 1H, Ar-H), 8.17 (dd, J = 7.88 Hz, 1.25 Hz, 1H, Ar-H), 10.95 (S, 1H, -NHCOCH3) IR (KBr, cm-1): 3240 (NH), 1740 (C=O), 1700 (C=O), 1660 (C=O) MS (m/e): 487 (54 M+), 387 (100, M+-CONNHCOCH3) Anal. Calcd.: C, 51.66; H, 3.10; N, 8.61 Found: C, 51.46; H, 3.12; N, 8.54.

AHP-9693 -245 EXAMPLE 4 N-[2-[(4-Bromo-2-fIuorophenyl)methyl]-2,3-dihydro-l,2',3,5'-tetraoxospiro[isoquinoline-4(lH),3'-pyrrolidin]-l'-yI]-l,l,l-trifIuoromethanesulfonamide To a cold (0°C) solution of r-amino-2-[(4-bromo-2-fluorophenyl)methyl]spiro[isoquinoline-4(lH),3'-pyrrolidine]-l,2',3,5'(2H)-tetrone (2.0 g, 4.48 mmol) in anhydrous CH2CI2 was added Et3N (3.12 mL, 22.4 mmol), followed by dropwise addition of (CF3SO2)2O (2.26 mL, 13.44 mmol). After stirring for 30 minutes the mixture was poured into H2O, acidified with HCl (2N) and extracted with EtOAc. Evaporation and purification by flash chromatography, on acid washed silica gel (hexane/EtOAc 1:1) gave a yellow solid (1.1 g, 42.5%, m.p. 98-100°C). 1H NMR (DMSO-d6, 400 MHz): δ 3.29 (d, J = 18.5 Hz, 1H, -HCHCO-), 3.5 (d, J = 18.5 Hz, 1H, -HCHCO-), 5.07 (s, 2H, -NCH2-), 7.18 (t, J = 8.1 Hz, 1H, Ar-H), 7.32 (dd, J = 8.3 Hz, 1.87 Hz, 1H, Ar-H), 7.38 d, J = 7.88 Hz, 1H, Ar-H),7.53 (dd, J = 9.96 Hz, 2.07 Hz, 1H, Ar20 H), 7.62 (t, J = 8.5 Hz, 1H, Ar-H), 7.78 (dt, J = 7.9 Hz, 1.25 Hz, 1H, Ar-H), 8-15 (dd, J = 7.9 Hz, 1.25 Hz, 1H, Ar-H) IR (KBr, cm-1): 3400 (NH), 1750 (C=O), 1670 (C=O) MS (m/e): 577 (94, M+), 387 (60, M+ -CONNHSO2CF3) Anal. Calcd.: C, 41.54; H, 2.09; N, 7.27 Found: C, 41.20; H, 2.03; N, 7.19. -25- AHP-9693/9694 The invention also provides new compounds having the formula Ia 3 in which R ,R and R are as defined under formula I and R8 and R7 are independently hydrogen, alkyl containing 1 to 12 carbon atoms, aryl, aryl (lower alkyl) wherein aryl contains 1 to 6 carbon atoms or R8 and R7 are joined to form alicyclic or hetercyclic rings selected from the group consisting of . /~\ ι wherein n = l-10 * wherein X=0,S, SO , SO-; \_/ 2 wherein X=O,S and N-R wherein R8 =H, lower alkyl containing 1 to 6 carbon atoms, aryl or aryKlower aryl) wherein aryl contain 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms .

A more preferred group of compounds of formula la is those compounds where R and R^ are hydrogen or halogen; R1 is a dihalogen substituted benzyl; R6 and V 6 R ar^ lower alkyl conca i n ing Ito 3 carbon atoms or R and R are joined to form alicyclic or hetercyclic rings selected from the group consisting of ,0 and -26- AHP-9693/9694 The most preferred compounds of the present invention are set forth below: 2-[(4-bromo-2-fluorophenyl)methyl]-l methylethylidene)amino]spiro[isoquinoline-4 (IH),3'5 pyrrolidine]-l,2, 3,5'(2H )-tetrone; 2-[(4-bromo-2-fluorophenyl )methyl]-6-fluoro-1' [(1-methylethy1idene) amino]spiro-[isoquinoline4(IH),3'-pyrrolidine]-l,2',3,5'( 2H )-tetrone; - [ (4-bromo-2-fluorophenyl)methyl]-1'-[(1-ethyΙΙΟ propylidene)amino]spiro[isoquinoline-4(IH),3'pyrrolidine]-l,2',3,5'(2H)-tetrone; 2-[(4-bromo-2-fluorophenyl)methyl]-l'-(cyclopentyl ideneami no) spiro [ isoquinoline-4(IH),3 ' pyrrolidine]-l,2',3,5'(2H)-tetrone; and 2-[(4-bromo-2-fluorophenyl)methyl]-1'-[tetrahydro-4Hpyran-4-ylidene) amino]spiro[isoquinoline-4(IH),3'pyrrolidine]-l,2',3,5'(2H)-tetrone.

Like the compounds of formula I, the compounds of formula Ia posses at least one asymmetric carbon atom.

Thus the invention encompasses the compounds Ia in racemic form or any optically active form. The compounds having formula Ia are useful in the same manner as the compounds having formula I. The results in the following table were obtained by the same test procedures as used for the results in the table above. -27- AHP-9693/9694 % Lowering Galacntoi The compounds having formula Ia may be prepared by a method which comprises reaction of a compound 12 3 having formula I wherein R , R and R are as defined · above and R and R are both hydrogen with a carbonyl -28- AHP-9693/9694 compound R^ R? CO wherein R^ and R? are as defined above or a reactive derivative thereof, for instance, an acetal. The method may be carried out in conventional manner for preparing Schiff bases. The preferred process of making the compounds Ia is by . . 1 3 reacting the compound of formula IX wherein R and R are as defined above with the carbonyl compound r7 co in the presence of a catalytic amount of any acid, for example, 10-camphorsulfonic acid. θ The following examples illustrate the preparation of compounds having formula Ia. -29ΑΗΡ-9693/9694 2-[(4-Bromo-2-fluorophenyl)methyl]-l'-[(leth yl propyl idene)amino]s pi rofisoquinolin e-4(lH),3'-pyr rol idine]-1,2',3,5'(2H)tetrone A mixture of r-amino-2-[(4-bromo-2-fluorophenyl)methyI]spiro[isoquinoline-4(lH),3'pyrrolidine]-l,2',3,5'(2H)-tetrone (2.0 g, 4.48 mmol), 3-pcntanone (20 mL) and 10camphorsulfonic acid (5 mg) was stirred ax 75°C for 20 minutes. Next, the volatiles were removed in vacuo and the residue was purified by flash chromatography on silica gel (hexane/EtOAc 2:1) to give a white solid (1.69 g, 73.7%, m.p. 144-146°C).

IH NMR (DMSO-dg, 400 MHz): 5 0.83 (t. J = 7.47 Hz, 3H, -CH9CH3). 1.08 (t, J = 7.26 Hz, 3H, -CH2£H3), 2.0 (q, J = 7.47 Hz, 2H, -CH2CH3), 2.5 (q, J = 7.26 Hz, 2H, -£H2CH3). 3.59 (s, 2H, -CH2CO-), 5.06 (q, J = 15.15 Hz, 2H, -NCifc-), 7.25 (t, J = 8.1 Hz, IH, Ar-H). 7.3 (dd, J = 8.1 Hz, 1.66 Hz, IH, Ar-H). 7.53 (dd, J = 9.96 Hz, 1.87 Hz, IH, Ar-H), 7.65 (dt, J = 8.3 Hz, 2.07 Hz, IH, Ar-H). 7.8 (m, 2H, Ar-H), 8-2 (dd, J = 8.3 Hz, 1.25 Hz, IH, Ar-H) ER (KBr cm’1): 1700 (C=O), 1670 (C=O) MS (m/e): 513(11, M+), 387 [28, M+-CONN=C(CH2CH3)2] Anal. Calcd.: C, 56.04; H, 4.12; N, 8.17 Found: C, 56.44; H, 4.10; N, 8.06.

The following compounds were prepared in substantially the same manner as that of Example 5: 2-[(4-Bromo-2-fluorophenyl)methy!]-l'-[(l-methyIethyIidene)amino]spiro[isoquinoline-4(lH),3'-pyrrolidine]-l,2',3,5'-(2H)-tetrone -30AHP-9693/9694 IR (KBr, cm*1): 1710 (C=O), 1670 (C=O) MS (m/e): 4S5 (78 M+), 387 [100, M+-CONNC(CH3CH3)2J Anal. Calcd.: C, 54.34; H, 3.52; N, 8.64 Found: C, 54.35; H, 3.62; N, 8.34 m.p. 127-129°C. 2-[(4.Bromo-2«fluorophenyI)methyI]-6-fluoro-r-[(l-methylethyIidene)amino]· spiro[isoquinoIine-4(lH),3'-pyrroIidine]«l,2',3,5'(2H)-tetrone IH NMR (DMSO-d^, 400 MHz): 5 1.71 (s, 3H, -CH3). 2.15 (s, 3H, -CH3). 3.55 (dd, J = 18.0 Hz, 2H, -CH?CQ-). 5.05 (dd, J = 15.4 Hz, 2H, -NCH?-). 7.14 (t, J = 8.3 Hz, IH, Ar-H), 7.35 (dd, J = 8.3 Hz, 1.6 Hz, IH, Ar-H), 7.52 (m, 2H, Ar-H), 7.88 (dd, J = 9.96 Hz, 2.5 Hz. IH, Ar-H), 8.27 (dd, J = 8.9 Hz, 6.1 Hz, IH, Ar-H) IR (KBr, cm-1): 1710 (C=O), 1665 (C=O) MS (m/e): 503 (10, M+), 405 [14, M+-CONN=C(CH3)2] Anal. Calcd.: C, 52.40; H, 3.20; N, 8.33 Found: C, 52.25; H, 3.08; N, 8.31 m.p. 152-154°C. 2-[(4-Bromo-2-nuorophenyl)methyl]-r-(cycIopentylideneamino)spiro[isoquinoIine-4(lH),3'-pyrroIidine]-l,2',3,5'(2H)-tetrone 'K NMR (DMSO-d$, 400 MHz): 5 1.7-1.78 (m, 4H, -CH?CH?CH?CH?-). 1.99 (t, J = 7.65 Ha. OH, -CH2CH2CH2CH2-). 2.5 (t, J = 7.26 Hz, 2H, -CH2CH2CH2O2-). 3.56(s, 2H,-CH<0-\ 5.0 (d, J = 15.36 Hz. IH, -NHCH-), 5.13 (d, J = 15.36 Hz, IH, -NH£H-), 7.16 (t, J = 8.3 Hr. IH, Ar-H). 7.35 (dd, J = 8.3 Hz. 1.87 Hz, IH, Ar-H). 7.53 (dd. J = 9.75 Hz, 1.87 Hz. IH. ArH), 7.65 (dt, J = 8.3 Hz, 2.07 Hz, IH, Ar-H). 7.SI (ra, 2H, Ar-H), 8.2 (dd, J = 7.9 Hz. 0.85 Hz, IH, Ar-H) IR (KBr, cm'1): 1705 (C=O), 1670 (C=O) M/S (m/e): 511 (8, M+) Anal. Calcd.: C, 56.26; H, 3.74; N, 8.20 Found: C, 56.60; H, 3.74; N, 8.11 m.p. 142-144°C. -31- ΑΗΡ - 9 69 3 / 9 694 2-[(4-Bromo-2-fluorophenyl)methyl]-l'-[(tetrahydro-4H-pyran-4-ylidene)amino]spiro[isoquinoIine-4(lH),3'-pyrrolidine]-l,2',3,5'(2H)-tetrone 1H NMR (DMSO-d^, 400 MHz): δ 2.16 (t, J = 5.6 Hz, 2H, -CH7CH9O-). 2.57 (t, J = 5.8 Hz, 2H, -CH2CH2O-), 3.5-3.6 (m, 4H, -CHzCO-, -CH2CH2O-), 3.76-3.83 (ro, 2H, -CH2HI2O-), 5.06 (dd, J = 15.15 Hz, 2H, -NCH?-). 7.15 (t, J = 8.1 Hz, 1H, Ar-H), 7.36 (dd, J = 8.3 Hz, l. 87 Hz, 1H, Ar-H), 7.55 (dd, J = 9.96 Hz, 2.07 Hz, 1H. Ar-H), 7.65 (m, 1H, Ar-H), 7.82 (m, 2H, Ar-H), 8.2 (dd, J = 7.68 Hz, 0.83 Hz, 1H, Ar-H) IR (KBr, cm-1): 1705 (C=O), 1655 (C=O) MS (m/c): 527 (62, M+) Anal. Calcd.: C, 54.56; H, 3.62; N, 7.95 Found: C, 54.40; H, 3.65; N, 7.91 m. p. 161-163°C.

Claims (21)

1. A compound of structural formula 1 2 R* and R are independently hydrogen, alkyl containing 1 to 6 carbon atoms, halogen, lower alkoxy containing 1 to 6 carbon atoms, trifluoromethyl, nitro, aryl or aryl (lower alkyl)oxy wherein aryl contains 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms; R^ is lower alkyl containing 1 to 6 carbon atoms, aryl, arvlClower alkyl) or dihalogen substituted arylClower alkyl) wherein aryl contains 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms; 4 5 6 7 X is -NR R or -N=CR R ; 4 D · R and R are independently hydrogen, alkyl containing 1 to 6 carbon atoms, aryl or ary1(loweralkyl) wherein aryl contains 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms, alkanoyl of 2 to 5 carbon atoms, carboalkoxy, alkvlsulfoxy, arylsulfoxy, alkylsulfonyl or arylsulfonyl wherein aryl contains 6 to 10 carbon atoms and alkoxy and alkyl contain 1 to 6 4 5 . . carbon atoms, or R and R together with the nitrogen atoms to which they are bonded represent a heterocyclic ring of 5 to 7 ring atoms and the pharmaceutically 4 5 acceptable salts thereof when R and R are hydrogen, 6 7 alkyl or aryl; and R and R are independently hydrogen, alkyl -33- AHP-9693/9694 containing 1 to 12 carbon atoms, arvl, aryl (lower aryl) wherein aryl contains 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms, or and R 7 are joined to form alicyclic and heterocyclic rings 5 selected from the group consisting of wherein n = 1-10; wherein X = O, S, SO, SO 2 ; /=% \=/ wherein X = 0, S; and wherein R 6 = H, lower alkyl containing 1 to 6 carbon atoms, aryl or aryl (lower alkyl)wherein aryi contain 6 to 10 carbon atoms and lower alkyl contains 1 to 6 carbon atoms.

2. A compound as claimed in claim 1 wherein X is -NR 4 R 5 . 1 2

3. A compound according^to claim 2 wherein R and R are hydrogen or halogen, R is a dihalogen substituted benzyl, R and R are hydrogen, alkanoyl of 2 to 5 carbon atoms, carboaLkoxy or trifluoromethylsulfonyl.

4. l-amino-2-[(4-bromo-2-fluorophenyl)methyl J 15 sp i rot i soquinoline-4(lH),3'-pyrrolidine]-l,2',3,5'(2H)tetrone.

5. l'-amino-2-((4-bromo-2-fluorophenyl)methyl] -6fluorospirotisoquinoline-4(1H),3'-pyrrolidine]1,2' , 3 , 5'(2H)-tetrone. 20 6. N-[2-((4-bromo-2-fLuoropheny1)methyl]-2,3dihydro-1,2',3,5'-tetraoxospirolisoquinoline-4(1H),3'pyrrolidin]-l'-ylJiminodicarbonic acid dimethyl ester. -34- ΑΗΡ-9693/9694 7 . Ν- [ 2 -[(4-bromo-2-fluorophenyl)methyl>2,3dihydro-1,2' ,3,5'-tetraoxospiro[i soqu inoi i ne-4(1H) , 3 ' pyrrolidin J-1'-yl] acetamide . 8. N-[2-C(4-bromo-2-fluorophenyl )methyl>2,3dihydro-1,2' ,3,5'-tetraoxospirofi soquinoli me-4(1H) , 3 ' pyrrolidin]-1'-yl ] -1,1,1-triflucromethansu1fonami de. 9 . A process for preparing a compound as claimed in claim 2 which comprises one of the following: a) acylating a compound of formula 4 5 R R NNH 2 (XIII) 4 5 .... wherein R and R are as defined in Claim 1 with a compound of formula CO.H (XIV) or an activated form thereof

6. . 1 2 wherein CO^R and is an ester function and R , R and R are as defined in Claim 1 to give a corresponding compound of formula I and if desired where possible isolating as a salt, or b) acylating a compound of formula I as defined in Claim 1 wherein one of R 4 and R 8 is hydrogen, the other is selected from hydrogen, lower alkyl, aryl or -35AHP-9693/9694 arylClower alkyl)- with an acylating agent containing the group r 8 co-, r 8 oco- or R 9 S(O) * n 8 . 9 . where R is alkyl and R is alkyl or aryl or, when n is 9 1, R also represents trifluoromethyl, to give a 4 corresponding compound of formula I wherein R is hydrogen, alkyl, aryl or arylClower alkyl) and R^ is alkanoyl, carboalkoxy, alkylsulfoxy, arylsulfoxy, alkylsulfonyl, arylsulfonyl or trifluoromethylsulfonyl 4 5 or R and R are both alkoxycarbonyl, alkanoyl, alkylsulfoxy, arylsulfoxy, alkylsulfonyl, arylsulfonyl or trifluoromethylsulfonyl, and if desired when possible isolating the compound of formula I as a salt.

7. 10. A process for preparing a compound of formula I substantially as hereinbefore described and illustrated in any one of Examples 4 . 1 step ( f ) , 1 step (g) , 2, 3 and 11. A compound of formula I or a salt thereof whenever prepared by a process as claimed in Claim 9 or Claim 10.

8. 12. A compound of formula I or a pharmaceutically acceptable salt thereof as claimed in any one of Claims 2 to 8 for use as a pharmaceutical.

9. 13. A pharmaceutical composition comprising a compound of formula I or a pharmaceutically acceptable salt thereof as claimed in any one of Claims 2 to 8 and a pharmaceutically acceptable carrier.

10. 14 A compound as claimed in claim 1, wherein X is -C=NR 6 R 7 . -36- AHP-9693/9694

11. 15. A compound as claimed in claim 14, wherein R 1 , 2 3 6 7 R and R are as defined in claim 3 and R and R are independently alkyl of 1 to 3 carbon atoms or R^ and R^ are joined to form -(CK^ - or -(CH^ ) 2 A “· 5

12. 16. 2-[(4-bromo-2-fluorophenyl)methylj-l'[(1-methylethyl idene )amino]spiro[isoquinoline-4(lH),3'pyrrolidine]-l,2',3,5'(2H)-tetrone.

13. 17 . 2 - [ (4-bromo-2-fluorophenyl 1methyl1-6-fluoro-l'[(1 -methylethyl idene ) amino ] spiro[ i soquinol ine-4 (IH ) , 3 ' 10 pyrrolidine]-l,2',3,5'(2H)-tetrone.

14. 18. 2 — [ f4-bromo-2-fluorophenyl)methylj-1'[<1-ethylpropy 1 idene)amino ]spiro[ isoquinoline-4 (IH ) , 3 ' pyrrolidine 1-1,2',3,5'(2H)-tetrone.

15. 19. 2-[(4-bromo-2-fluorophenyl)methyl 1-1'15 (cyclopentylideneamino)spiro[isoquinoline-4(lH),3'pyrrolidine]-l,2',3,5'(2H)-tetrone.

16. 20. 2 — [(4-bromo-2-fluorophenyllmethyl]-1'(tetrahydro-4H-pyran-4-ylidene) spi ro[isoquinoline-4(IH) ,3'-pyrrolidine 1-1,2',3,5'(2H)-tetrone. 20

17. 21. A method of preparation of a compound as claimed in claim 14, wherein a compound as claimed in claim 2 4 5 . where R and R are both hydrogen is reacted with a carbonyl compound having the formula R^ R^ CO where R^ and R? are as defined in claim 1 or a reactive 25 derivative of the said carbonyl compound.

18. 22. A method as claimed in claim 21, carried out substantially as described with reference to Example 5 herein . -37AHP-9693/9694

19. 23. A compound as claimed in claim 14, whenever prepared by a process as claimed in claim 21 or 22.

20. 24. A pharmaceutical composition comprising a compound as claimed in any one of claims 14 to 20 and 23 in combination or association with a pharmaceutically acceptable carrier.

21. 25. A process of preparation of a pharmaceutical composition claimed in claim 24, which comprises bringing a compound as claimed in any one of claims 14 to 20 and 23 into combination or association with a pharmaceutically acceptable carrier.