1,2-BENZISOXAZOLE-3-CARBOXYLIC ACID ETHYL ESTER

10percent Palladium on carbon (1.5g) and triethylamine (7.5 g, 82.4 mmol) were added to a solution of ethyl 6-bromobenzisoxazole-3-carboxylate (20g, 0. 081mol) in ethanol (300ml) at 0 °C under an atmosphere of nitrogen. The nitrogen atmosphere was removed by evacuation and replaced with hydrogen gas, and the reaction mixture was maintained for 1 hour. The hydrogen atmosphere was removed by evacuation and replaced with nitrogen gas, and the palladium removed by filtration through Celite. The filter cake was washed with ethanol (3 x 50 mL) and the filtrates were concentrated. The residue was dissolved in dichloromethane (200 mL) and the solution was washed with water (4 x 50 mL), dried (sodium sulfate) and evaporated to provide 13.0 g of the product as a yellow solid (96percent). The ester was saponified using sodium hydroxide to provide the acid. The acid was coupled with the bicyclobase according to procedure A. Literature reference: Angell, R. M.; Baldwin, I. R.; Bamborough, P.; Deboeck, N. M.; Longstaff, T.; Swanson, S. W004010995A1 The following acid was prepared using this method: 1, 2-Benzisoxazole-3-carboxylic acid.Diethyl malonate (12.6 g, 79 mmol) was added to a suspension of sodium hydride (3.16 g, 132 mmol) in dimethylsulfoxide (60 ml) over 30 min. The temperature of the reaction rose to 60 °C and the mixture clarified. 1, 4-Dibromo-2-nitrobenzene (10 g, 36.0 mmol) was added and the solution was maintained for 2 h at 100 °C. The reaction mixture was allowed to cool to rt and was poured into ice (300g-400g). The precipitated solids were isolated by filtration and dried to provide 11.0 g of the product (89percent). The ester (11.0 g, 32.0 mmol) was diluted with a 2 N solution of sodium hydroxide (32 mL, 63 mmol) and the reaction mixture was maintained at room temperature for 16 h. The aqueous layer was extracted with dichloromethane (20 mL) and was acidified. The precipitated solids were isolated by filtration and dried to provide 7.00 g of the acid (89percent). Sulfuric acid (1 mL) was added to a solution of the acid (7.00 g, 27.0 mmol) in ethanol (60 ml). The reaction mixture was warmed to reflux, maintained for 2 h, and was concentrated under reduce pressure. The residue was partitioned between ethyl acetate (250 mL) and saturated sodium carbonate (50 mL) and the organic layer was washed with saturated sodium carbonate (50 mL) and brine (50 mL). The organic layer was dried (sodium sulfate) and concentrated to provide 8.00 g (98percent) of the ester as a liquid. Under N2 atmosphere, sodium ethylate was formed with sodium (33.5 g, 1.46 mol) in ethanol (1.0 L). Isoamylnitrite (225 mL) was added to a solution of the ester (420 g, 1.46 mol) in ethanol (3 L) in a 10 L three-necked round bottom flask and the mixture was warmed to 60 °C. A solution of sodium ethoxide, prepared from sodium metal (33.5 g, 1.46 mmol) in ethanol (1 L) was added dropwise and the reaction mixture was maintained for 2 h. The reaction mixture was allowed to cool to rt and was neutralized with 2 N hydrochloric acid. The reaction mixture was extracted with ethyl acetate (4 x 2L) and the combined organic layers were washed with water (2 x 1 L) and brine (2 x 1 L) and dried (sodium sulfate). The residue was purified by chromatography (1/1 to 0/1 hexane/ethyl acetate) to provide 110 g of the product ( 28percent). 10percent Palladium on carbon (1.5g) and triethylamine (7.5 g, 82.4 mmol) were added to a solution of ethyl 6-bromobenzisoxazole-3-carboxylate (20g, 0.081mol) in ethanol (300ml) at 0 °C under an atmosphere of nitrogen. The nitrogen atmosphere was removed by evacuation and replaced with hydrogen gas, and the reaction mixture was maintained for 1 hour. The hydrogen atmosphere was removed by evacuation and replaced with nitrogen gas, and the palladium removed'by filtration through Celite. The filter cake was washed with ethanol (3 x 50 mL) and the filtrates were concentrated. The residue was- dissolved in dichloromethane (200 mL) and the solution was washed with water (4 x 50 mL), dried (sodium sulfate) and evaporated to provide 13.0 g of the product as a yellow solid (96percent). The ester was saponified using sodium hydroxide to provide the acid. The acid was coupled with 1, 4-diazabicyclo[3.2.2]nonane according to procedure A.10percent Palladium on carbon (1.5 g) and triethylamine (7.5 g, 82.4 mmol) were added to a solution of ethyl 6-bromobenzisoxazole-3-carboxylate (20 g, 0.081 mol) in ethanol (300ml) at 0° C. under an atmosphere of nitrogen. The nitrogen atmosphere was removed by evacuation and replaced with hydrogen gas, and the reaction mixture was maintained for 1 hour. The hydrogen atmosphere was removed by evacuation and replaced with nitrogen gas, and the palladium removed by filtration through Celite. The filter cake was washed with ethanol (3.x.50 mL) and the filtrates were concentrated. The residue was dissolved in dichloromethane (200 mL) and the solution was washed with water (4.x.50 mL), dried (sodium sulfate) and evaporated to provide 13.0 g of the product as a yellow solid (96percent). The ester was saponified using sodium hydroxide to provide the acid. The acid was coupled with the bicyclobase according to procedure A.A solution of the nitro oxime a (5.0 g, 21.0 mmol) prepared according to the procedures described by Kemp et al. (/. Am. Chem. Soc. 1975, 97, 7305-7312) in DMF (30 mL) was added drop wise over 25 min to a vigorously stirred suspension of hexane-washed NaH (60percent in mineral oil, 840 mg, 21.0 mmol) in DMF (40 mL) under N10percent Palladium on carbon (1.5g) and triethylamine (7.5 g, 82.4 mmol) were added to a solution of ethyl 6-bromobenzisoxazole-3-carboxylate (20g, 0. 081mol) in ethanol (300ml) at 0 °C under an atmosphere of nitrogen. The nitrogen atmosphere was removed by evacuation and replaced with hydrogen gas, and the reaction mixture was maintained for 1 hour. The hydrogen atmosphere was removed by evacuation and replaced with nitrogen gas, and the palladium removed by filtration through Celite. The filter cake was washed with ethanol (3 x 50 mL) and the filtrates were concentrated. The residue was dissolved in dichloromethane (200 mL) and the solution was washed with water (4 x 50 mL), dried (sodium sulfate) and evaporated to provide 13.0 g of the product as a yellow solid (96percent). The ester was saponified using sodium hydroxide to provide the acid. The acid was coupled with the bicyclobase according to procedure A. Literature reference: Angell, R. M.; Baldwin, I. R.; Bamborough, P.; Deboeck, N. M.; Longstaff, T.; Swanson, S. W004010995A1 The following acid was prepared using this method: 1, 2-Benzisoxazole-3-carboxylic acid.Diethyl malonate (12.6 g, 79 mmol) was added to a suspension of sodium hydride (3.16 g, 132 mmol) in dimethylsulfoxide (60 ml) over 30 min. The temperature of the reaction rose to 60 °C and the mixture clarified. 1, 4-Dibromo-2-nitrobenzene (10 g, 36.0 mmol) was added and the solution was maintained for 2 h at 100 °C. The reaction mixture was allowed to cool to rt and was poured into ice (300g-400g). The precipitated solids were isolated by filtration and dried to provide 11.0 g of the product (89percent). The ester (11.0 g, 32.0 mmol) was diluted with a 2 N solution of sodium hydroxide (32 mL, 63 mmol) and the reaction mixture was maintained at room temperature for 16 h. The aqueous layer was extracted with dichloromethane (20 mL) and was acidified. The precipitated solids were isolated by filtration and dried to provide 7.00 g of the acid (89percent). Sulfuric acid (1 mL) was added to a solution of the acid (7.00 g, 27.0 mmol) in ethanol (60 ml). The reaction mixture was warmed to reflux, maintained for 2 h, and was concentrated under reduce pressure. The residue was partitioned between ethyl acetate (250 mL) and saturated sodium carbonate (50 mL) and the organic layer was washed with saturated sodium carbonate (50 mL) and brine (50 mL). The organic layer was dried (sodium sulfate) and concentrated to provide 8.00 g (98percent) of the ester as a liquid. Under N2 atmosphere, sodium ethylate was formed with sodium (33.5 g, 1.46 mol) in ethanol (1.0 L). Isoamylnitrite (225 mL) was added to a solution of the ester (420 g, 1.46 mol) in ethanol (3 L) in a 10 L three-necked round bottom flask and the mixture was warmed to 60 °C. A solution of sodium ethoxide, prepared from sodium metal (33.5 g, 1.46 mmol) in ethanol (1 L) was added dropwise and the reaction mixture was maintained for 2 h. The reaction mixture was allowed to cool to rt and was neutralized with 2 N hydrochloric acid. The reaction mixture was extracted with ethyl acetate (4 x 2L) and the combined organic layers were washed with water (2 x 1 L) and brine (2 x 1 L) and dried (sodium sulfate). The residue was purified by chromatography (1/1 to 0/1 hexane/ethyl acetate) to provide 110 g of the product ( 28percent). 10percent Palladium on carbon (1.5g) and triethylamine (7.5 g, 82.4 mmol) were added to a solution of ethyl 6-bromobenzisoxazole-3-carboxylate (20g, 0.081mol) in ethanol (300ml) at 0 °C under an atmosphere of nitrogen. The nitrogen atmosphere was removed by evacuation and replaced with hydrogen gas, and the reaction mixture was maintained for 1 hour. The hydrogen atmosphere was removed by evacuation and replaced with nitrogen gas, and the palladium removed'by filtration through Celite. The filter cake was washed with ethanol (3 x 50 mL) and the filtrates were concentrated. The residue was- dissolved in dichloromethane (200 mL) and the solution was washed with water (4 x 50 mL), dried (sodium sulfate) and evaporated to provide 13.0 g of the product as a yellow solid (96percent). The ester was saponified using sodium hydroxide to provide the acid. The acid was coupled with 1, 4-diazabicyclo[3.2.2]nonane according to procedure A.10percent Palladium on carbon (1.5 g) and triethylamine (7.5 g, 82.4 mmol) were added to a solution of ethyl 6-bromobenzisoxazole-3-carboxylate (20 g, 0.081 mol) in ethanol (300ml) at 0° C. under an atmosphere of nitrogen. The nitrogen atmosphere was removed by evacuation and replaced with hydrogen gas, and the reaction mixture was maintained for 1 hour. The hydrogen atmosphere was removed by evacuation and replaced with nitrogen gas, and the palladium removed by filtration through Celite. The filter cake was washed with ethanol (3.x.50 mL) and the filtrates were concentrated. The residue was dissolved in dichloromethane (200 mL) and the solution was washed with water (4.x.50 mL), dried (sodium sulfate) and evaporated to provide 13.0 g of the product as a yellow solid (96percent). The ester was saponified using sodium hydroxide to provide the acid. The acid was coupled with the bicyclobase according to procedure A.Compound 41-c (8.00 g, 33.59 mmol, 1.00 eq) was dissolved in diglyme (80.00 mL), and the above solution was added dropwise to a mixed solution of sodium hydride (2.02 g, 50.39 mmol, purity of 60percent, 1.50 eq) and diglyme (110.00 mL) with vigorously stirring under the protection of nitrogen gas. The reaction solution was slowly warmed up to 150°C, and stirred for 5 hours. After the reaction was completed, the reaction solution was added with 200 mL of water, and extracted with ethyl acetate (400 mL). The organic phase was washed with water (150 mL 3 2), dried over anhydrous sodium sulfate, filtered, concentrated, and then dissolved in heated petroleum ether. The above solution was cooled down to 0°C, the precipitated solid was filtered, and the product of compound 41-d (3.32 g, yield: 44percent) as a pale yellow solid was obtained by concentration. 1H NMR (400 MHz, DMSO-d6) δ=8.04-8.11 (m, 1H), 7.91 (d, J=8.53 Hz, 1H), 7.76 (t, J=7.78 Hz, 1H), 7.55 (t, J=7.53 Hz, 1H), 4.48 (q, J=7.36 Hz, 2H), 1.40 (t, J=7.03 Hz, 3H).A solution of the nitro oxime a (5.0 g, 21.0 mmol) prepared according to the procedures described by Kemp et al. (/. Am. Chem. Soc. 1975, 97, 7305-7312) in DMF (30 mL) was added drop wise over 25 min to a vigorously stirred suspension of hexane-washed NaH (60percent in mineral oil, 840 mg, 21.0 mmol) in DMF (40 mL) under NTo a solution of

Molecular Weight:191.18
XLogP3:2.3
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:3
Exact Mass:191.058243149
Monoisotopic Mass:191.058243149
Topological Polar Surface Area:52.3
Heavy Atom Count:14
Complexity:219
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes