tert-butyl 4-bromo-5-oxoazepane-1-carboxylate

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

Procedure: The title compound was prepared by the following reaction sequence: i) treatment of the 5-bromo-azepan-4-one hydrobromide (1:1) [Ger. Offen. (1989), DE 38207751] with di-t-butyldicarbonate in dioxane/aq. sodium hydrogen carbonate solution to yield the 4-bromo-5-oxo-azepane-1-carboxylic acid tert-butyl ester; ii) treatment of the 4-bromo-5-oxo-azepane-1-carboxylic acid tert-butyl ester with thioacetamide in ethanol in the presence of triethylamine at reflux to give the 2-methyl-4,5,7,8-tetrahydro-thiazolo[4,5-d]azepine-6-carboxylic acid tert-butyl ester; iii) conversion of the 2-methyl-4,5,7,8-tetrahydro-thiazolo[5-d]azepine-6-carboxylic acid tert-butyl ester into the 2-methyl-5,6,7,8-tetrahydro-4H-thiazolo[4,5-d]azepine by removal of the tert-butyloxycarbonyl function with hydrogen chloride (aqueous, 37%) in methanol at room temperature.

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

Procedure: To a solution tert-butyl 4-oxoazepane-1-carboxylate (429.2, 11.0 g, 51.6 mmol, 1.00 equiv) in chloroform (220 mL) 0° C. was added dropwise solution of Br2 (12.4 g, 77.6 mmol, 1.50 equiv) in chloroform (110 mL). The resulting mixture was stirred at room temperature overnight. The formed solids were collected by filtration and taken up in 200 mL of dichloromethane. Et3N (12.2 g) and (Boc)2O (8.70 g, 40.3 mmol, 1.00 equiv) were added to the mixture at 0° C. The resulting solution was stirred for 3 h at room temperature, and then concentrated under pressure. The crude residue was purified by silica gel chromatography using ethyl acetate/petroleum ether (1:10) as eluent to give 4.00 g (27%) of the title compound as a yellow oil. The formed solids were collected by filtration The resulting solution was stirred for 3 h at room temperature concentrated under pressure The crude residue was purified by silica gel chromatography

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-bromohexahydro-5-oxo-1H-azepine-1-carboxylic acid 1,1-dimethylethyl ester and 3-bromohexahydro-4-oxo-1H-azepine-1-carboxylic acid 1,1-dimethylethyl ester (0.22 g, 0.50 mmol) and trans-cinnamamide (0.06 g, 0.38 mmol) was supported in silica gel (1 g) and mechanically stirred at 120° C. for 3 days. The product was eluted from the silica gel with a 7M solution of ammonia in MeOH and the filtrate evaporated in vacuo. The crude product was basified with a saturated solution of NaHCO3 and extracted with DCM. The organic layer was separated, dried (Na2SO4), filtered and the solvent evaporated in vacuo to yield 5,6,7,8-tetrahydro-2-[(E)-2-phenylethenyl]-4H-oxazolo[4,5-d]azepine (0.045 g, 15% yield, 32% pure) as a brown solid that was used in the next step without further purification. C15H16N2O LCMS: Rt 1.60, m/z 241 [M+H]+ (method 5). The compound 3-bromohexahydro-4-oxo-1H-azepine-1-carboxylic acid 1,1-dimethylethyl ester was not observed in the crude of the reaction. The product was eluted from the silica gel with a 7M solution of ammonia in MeOH the filtrate evaporated in vacuo extracted with DCM The organic layer was separated dried (Na2SO4) filtered the solvent evaporated in vacuo

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 10-mL sealed tube, was placed methyl 5-formyl-2,4-dimethylbenzoate (compound 83.2, 500 mg, 2.60 mmol), tert-butyl 4-bromo-5-oxoazepane-1-carboxylate (compound 82.3, 1.1 g, 3.8 mmol), ammonium hydroxide (25%) (1.2 mL, 7.8 mmol), ammonium acetate (900 mg, 11.7 mmol) in N,N-dimethylformamide (6 mL). The resulting mixture was stirred for 3 h at 130° C. behind a blast shield, then cooled to room temperature and diluted with ethyl acetate (150 mL). The mixture was washed with brine (5×20 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography with dichloromethane/methanol (10:1) as the eluent to yield 0.80 g (46%) of the title compound as yellow oil. Into a 10-mL sealed tube cooled to room temperature The mixture was washed with brine (5×20 mL) dried (Na2SO4) filtered concentrated under reduced pressure The residue was purified by silica gel column chromatography with dichloromethane/methanol (10:1) as the eluent

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 100-mL round-bottom flask, was placed a mixture of methyl 4-cyclobutyl-5-formyl-2-methylbenzoate (compound 82.5, 300 mg, 1.29 mmol), ammonium acetate (449 mg, 5.83 mmol), tert-butyl 4-bromo-5-oxoazepane-1-carboxylate (compound 82.3, 564 mg, 1.93 mmol) and ammonium hydroxide (25%) (597 μL, 3.87 mmol) in N,N-dimethylformamide (8 mL). The resulting mixture was stirred for 4 h at 130° C., then cooled and quenched with water/ice (10 mL). The aqueous phase was extracted with ethyl acetate (2×30 mL) and the combined organic layers were washed with brine (3×10 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography with ethyl acetate/petroleum ether (1/1) as the eluent to yield 0.10 g (18%) of the title compound as a white solid. Into a 100-mL round-bottom flask, was placed cooled quenched with water/ice (10 mL) The aqueous phase was extracted with ethyl acetate (2×30 mL) the combined organic layers were washed with brine (3×10 mL) dried (Na2SO4) filtered concentrated under reduced pressure The residue was purified by silica gel column chromatography with ethyl acetate/petroleum ether (1/1) as the eluent

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

Procedure: To a solution tert-butyl 4-oxoazepane-1-carboxylate (compound 82.2, 11.0 g, 51.6 mmol) in chloroform (220 mL) at 0° C. was added drop-wise a solution of bromine (3.98 mL, 77.6 mmol) in chloroform (110 mL). The resulting mixture was stirred at room temperature overnight, then the solids that formed were collected by filtration and dissolved in dichloromethane (200 mL). Triethylamine (16.8 mL, 121 mmol) and (Boc)2O (8.70 g, 40.3 mmol) were added to the mixture at 0° C. and the resulting solution was stirred for 3 h at room temperature, and then concentrated under reduced pressure. The crude residue was purified by silica gel chromatography using ethyl acetate/petroleum ether (1:10) as the eluent to give 4.0 g (27%) of the title compound as a yellow oil. the solids that formed were collected by filtration dissolved in dichloromethane (200 mL) the resulting solution was stirred for 3 h at room temperature concentrated under reduced pressure The crude residue was purified by silica gel chromatography

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

Procedure: The title compound was prepared by the following reaction sequence: i) treatment of the 5-bromo-azepan-4-one hydrobromide (1:1) [Ger. Offen. (1989), DE 38207751] with di-t-butyldicarbonate in dioxane/aq. sodium hydrogen carbonate solution to yield the 4-bromo-5-oxo-azepane-1-carboxylic acid tert-butyl ester; ii) treatment of the 4-bromo-5-oxo-azepane-1-carboxylic acid tert-butyl ester with thioacetamide in ethanol in the presence of triethylamine at reflux to give the 2-methyl-4,5,7,8-tetrahydro-thiazolo[4,5-d]azepine-6-carboxylic acid tert-butyl ester; iii) conversion of the 2-methyl-4,5,7,8-tetrahydro-thiazolo[5-d]azepine-6-carboxylic acid tert-butyl ester into the 2-methyl-5,6,7,8-tetrahydro-4H-thiazolo[4,5-d]azepine by removal of the tert-butyloxycarbonyl function with hydrogen chloride (aqueous, 37%) in methanol at room temperature.

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

Procedure: To a solution tert-butyl 4-oxoazepane-1-carboxylate (429.2, 11.0 g, 51.6 mmol, 1.00 equiv) in chloroform (220 mL) 0° C. was added dropwise solution of Br2 (12.4 g, 77.6 mmol, 1.50 equiv) in chloroform (110 mL). The resulting mixture was stirred at room temperature overnight. The formed solids were collected by filtration and taken up in 200 mL of dichloromethane. Et3N (12.2 g) and (Boc)2O (8.70 g, 40.3 mmol, 1.00 equiv) were added to the mixture at 0° C. The resulting solution was stirred for 3 h at room temperature, and then concentrated under pressure. The crude residue was purified by silica gel chromatography using ethyl acetate/petroleum ether (1:10) as eluent to give 4.00 g (27%) of the title compound as a yellow oil. The formed solids were collected by filtration The resulting solution was stirred for 3 h at room temperature concentrated under pressure The crude residue was purified by silica gel chromatography