ethyl 3-oxothiane-2-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the solution of 6.35 g (0.05 mole) of 5-amino-3-dimethylamino-1H-1,2,4-triazole, 2.5 ml of acetic acid and 12.5 ml of dimethylformamide, 9.4 g (0.05 mole) of ethyl 3-oxo-3,4,5,6-tetrahydro-2H-thiopyrane-2-carboxylate are added and the reaction mixture is boiled for 40 minutes. The precipitated product is filtered off from the hot solution, then washed with acetic acid and i-propanol and recrystallized from dimethylformamide. Thus 8.2 g (65.2%) of 2-dimethylamino-5,7,8,9-tetrahydrothiopyrano[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine-5(10H)-one are obtained. M.p.: higher than 350° C. The precipitated product is filtered off from the hot solution washed with acetic acid and i-propanol recrystallized from dimethylformamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the solution of 6.5 g (0.05 mole) of 5-amino-3-methylthio-1H-1,2,4-triazole, 2.5 ml of acetic acid and 12.5 ml of dimethylformamide 9.4 g (0.05 mole) of ethyl 3-oxo-3,4,5,6-tetrahydro-2H-thiopyrane-2-carboxylate are added and the reaction mixture is boiled for 60 minutes. The precipitated product is filtered off from the hot solution, then washed with acetic acid and i-propanol and recrystallized from dimethylformamide. Thus 6.5 g (51.1%) of 2-methylthio-5,7,8,9-tetrahydrothiopyrano[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine-5(10H)-one are obtained. M.p.: higher than 350° C. The precipitated product is filtered off from the hot solution washed with acetic acid and i-propanol recrystallized from dimethylformamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the solution of 6.5 g (0.05 mole) of 5-amino-3-methylthio-1H-1,2,4-triazole, 2.5 ml of acetic acid and 12.5 ml of dimethylformamide 9.4 g (0.05 mole) of ethyl 3-oxo-3,4,5,6-tetrahydro-2H-thiopyrane-2-carboxylate are added and the reaction mixture is boiled for 60 minutes. The precipitated product is filtered off from the hot solution, then washed with acetic acid and i-propanol and recrystallized from dimethylformamide. Thus 6.5 g (51.1%) of 2-methylthio-5,7,8,9-tetrahydrothiopyrano[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine-5(10H)-one are obtained. M.p.: higher than 350° C. The precipitated product is filtered off from the hot solution washed with acetic acid and i-propanol recrystallized from dimethylformamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 16.7 g (0.1 mole) of 5-amino-3-piperidino-1H-1,2,4-triazole are dissolved in 10 ml of acetic acid and 18.8 g (0.1 mole) of ethyl 3-oxo-3,4,5,6-tetrahydro-2H-thiopyrane-2-carboxylate are added, then the reaction mixture is boiled for 10 minutes. The thick crystal mass thus obtained is diluted with 100 ml of water, the precipitated product is filtered off, washed with i-propanol and recrystallized from dimethylformamide. Thus 23.3 g (82.2%) of 2-piperidino-5,7,8,9-tetrahydrothiopyrano[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine-5(10H)-one are obtained with a melting point above 350° C. The thick crystal mass thus obtained the precipitated product is filtered off washed with i-propanol recrystallized from dimethylformamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 3-oxothiane-2-carboxylic acid ethyl ester (2.0 g), methanol (8 ml), and methyl orthoformate (20 ml) is added p-toluenesulfonic acid monohydrate (120 mg). After refluxing overnight, the mixture is concentrated, diluted with ethyl acetate, washed with water, dried, and concentrated to give 3,3-dimethoxythiane-2-carboxylic acid ethyl ester (1.32 g). After refluxing overnight the mixture is concentrated diluted with ethyl acetate washed with water dried concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 3-oxothiane-2-carboxylic acid ethyl ester (2.0 g), methanol (8 ml), and methyl orthoformate (20 ml) is added p-toluenesulfonic acid monohydrate (120 mg). After refluxing overnight, the mixture is concentrated, diluted with ethyl acetate, washed with water, dried, and concentrated to give 3,3-dimethoxythiane-2-carboxylic acid ethyl ester (1.32 g). After refluxing overnight the mixture is concentrated diluted with ethyl acetate washed with water dried concentrated

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium metal (3.94 g, 0.17 g atom) was dissolved in methanol (150 ml) and cyclopropylcarboxamidine hydrochloride (21.0 g, 0.174 mol) was added followed after 1/4 hour stirring by the addition of ethyl 3-oxotetrahydrothiopyran-2-carboxylate (27.2 g, 0.145 mol). The reaction mixture was stirred at 25° C. for 18 hours then treated with ice water (200 ml) and neutralized with acetic acid to give 24.6 g of the title compound which melted at 249°-250° C. followed after 1/4 hour

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium metal (3.94 g, 0.17 g atom) was dissolved in methanol (150 ml) and cyclopropylcarboxamidine hydrochloride (21.0 g, 0.174 mol) was added followed after 1/4 hour stirring by the addition of ethyl 3-oxotetrahydrothiopyran-2-carboxylate (27.2 g, 0.145 mol). The reaction mixture was stirred at 25° C. for 18 hours then treated with ice water (200 ml) and neutralized with acetic acid to give 24.6 g of the title compound which melted at 249°-250° C. followed after 1/4 hour

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 5 g (219 mmol) of sodium in 13 mL of anhydrous EtOH and 88 mL of ether are added dropwise, at 0° C. and under argon, 20.5 g (87.5 mmol) of ethyl 4-[(2-ethoxy-2-oxoethyl)sulfanyl]butanoate. After stirring for 18 hours at room temperature, the reaction mixture is poured into a mixture of AcOH (12 mL)/ice (70 g). The medium is then concentrated under reduced pressure, and the residue obtained is taken up in 100 mL of ether, washed with brine (2×50 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The residue obtained is purified by chromatography on silica gel, eluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc. 5.64 g of ethyl 3-oxotetrahydro-2H-thiopyrane-2-carboxylate are obtained in the form of a yellow oil. The medium is then concentrated under reduced pressure the residue obtained washed with brine (2×50 mL) dried over Na2SO4 filtered concentrated under reduced pressure The residue obtained is purified by chromatography on silica gel eluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 5 g (219 mmol) of sodium in 13 mL of anhydrous EtOH and 88 mL of ether are added dropwise, at 0° C. and under argon, 20.5 g (87.5 mmol) of ethyl 4-[(2-ethoxy-2-oxoethyl)sulfanyl]butanoate. After stirring for 18 hours at room temperature, the reaction mixture is poured into a mixture of AcOH (12 mL)/ice (70 g). The medium is then concentrated under reduced pressure, and the residue obtained is taken up in 100 mL of ether, washed with brine (2×50 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The residue obtained is purified by chromatography on silica gel, eluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc. 5.64 g of ethyl 3-oxotetrahydro-2H-thiopyrane-2-carboxylate are obtained in the form of a yellow oil. The medium is then concentrated under reduced pressure the residue obtained washed with brine (2×50 mL) dried over Na2SO4 filtered concentrated under reduced pressure The residue obtained is purified by chromatography on silica gel eluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc