1-diazo-3,3-dimethylbutan-2-one

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of 2 mL (2.3 g, 16 mmol) of boron trifluoride etherate in 20 mL of chloroacetonitrile at 0° C. was added a solution of 1.33 g (10 mmol) of 1-diazo-3,3-dimethyl-2-butanone in 5 mL of chloroacetonitrile dropwise. The resulting solution was stirred at 0° C. for 0.5 h. The reaction mixture was added to saturated aqueous sodium bicarbonate solution to neutralize the acid and the product was extracted three times with dichloromethane. The combined extracts was dried (sodium sulfate), concentrated and purified by flash column chromatography (Merck silica, 25×200 mm, dichloromethane) to give 1.1 g of 2-(chloromethyl)-5-t-butyloxazole as a yellow liquid (6.4 mmol, 64% overall from the acid chloride). the product was extracted three times with dichloromethane The combined extracts was dried (sodium sulfate) concentrated purified by flash column chromatography (Merck silica, 25×200 mm, dichloromethane)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To the diazomethane solution at 0° C. was added a solution of 1.23 mL (1.21 g, 10 mmol, Aldrich) of trimethylacetyl chloride in 1 mL of diethyl ether dropwise with stirring. The resulting mixture was kept at 0° C. for 16 h. The solution was sparged with argon to remove the excess diazomethane and diethyl ether was removed under reduced pressure to give 1.33 g (10 mmol, 100%) of crude 1-diazo-3,3-dimethyl-2-butanone as a yellow liquid. The solution was sparged with argon to remove the excess diazomethane and diethyl ether was removed under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To the diazomethane solution at 0° C. was added a solution of 1.23 mL (1.21 g, 10 mmol, Aldrich) of trimethylacetyl chloride in 1 mL of diethyl ether dropwise with stirring. The resulting mixture was kept at 0° C. for 16 h. The solution was sparged with argon to remove the excess diazomethane and diethyl ether was removed under reduced pressure to give 1.33 g (10 mmol, 100%) of crude 1-diazo-3,3-dimethyl-2-butanone as a yellow liquid. The solution was sparged with argon to remove the excess diazomethane and diethyl ether was removed under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a stirred solution of chloroacetonitrile (40 mL) and boron trifluoride etherate (20 mL, 0.16 mmol) at 0° C. was added 1-diazo-3,3-dimethyl-2-butanone in chloroacetonitrile (40 mL) dropwise over a period of 20 minutes. After addition was complete, the mixture was stirred at 0° C. for one hour and then partitioned between saturated NaHCO3 solution (700 mL) and CH2Cl2 (500 mL). The aqueous solution was. extracted with CH2Cl2 (500 mL) and the combined organic layers were washed with brine (400 mL) and dried over MgSO4. After filtration, the solution was concentrated and then distilled under vacuum using an oil bath temperature of 40° C. The 2-(chloromethyl)-5-t-butyloxazole (9.2 g, 44% overall from the acid chloride, C8H12CINO, MS m/e 174 (M+H)+) was obtained as a light yellow oil. After addition partitioned between saturated NaHCO3 solution (700 mL) and CH2Cl2 (500 mL) extracted with CH2Cl2 (500 mL) the combined organic layers were washed with brine (400 mL) dried over MgSO4 After filtration the solution was concentrated distilled under vacuum temperature of 40° C

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To the diazomethane solution was added a solution of trimethylacetyl chloride (15 mL, 0.12 mol) in ether (100 mL) dropwise over 40 minutes. After addition was complete, the solution was allowed to warm slowly overnight to room temperature. The solution was purged with a flow of nitrogen gas to remove any excess diazomethane and the resulting solution was concentrated to give 1-diazo-3,3-dimethyl-2-butanone as a yellow oil which was used directly in the next step. After addition to warm slowly overnight to room temperature The solution was purged with a flow of nitrogen gas to remove any excess diazomethane the resulting solution was concentrated

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a stirred solution of chloroacetonitrile (40 mL) and boron trifluoride etherate (20 mL, 0.16 mmol) at 0° C. was added 1-diazo-3,3-dimethyl-2-butanone in chloroacetonitrile (40 mL) dropwise over a period of 20 minutes. After addition was complete, the mixture was stirred at 0° C. for one hour and then partitioned between saturated NaHCO3, solution (700 mL) and CH2Cl2 (500 mL). The aqueous solution was extracted with CH2Cl2 (500 mL) and the combined organic layers were washed with brine (400 mL) and dried over MgSO4. After filtration, the solution was concentrated and then distilled under vacuum using an oil bath temperature of 40° C. The 2-(chloromethyl)-5-t-butyloxazole (9.2 g, 44% overall from the acid chloride, C8H12ClNO, MS m/e 174 (M+H)+) was obtained as a light yellow oil. After addition partitioned between saturated NaHCO3, solution (700 mL) and CH2Cl2 (500 mL) The aqueous solution was extracted with CH2Cl2 (500 mL) the combined organic layers were washed with brine (400 mL) dried over MgSO4 After filtration the solution was concentrated distilled under vacuum temperature of 40° C

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To the diazomethane solution was added a solution of trimethylacetyl chloride (15 mL, 0.12 mol) in ether (100 mL) dropwise over 40 minutes. After addition was complete, the solution was allowed to warm slowly overnight to room temperature. The solution was purged with a flow of nitrogen gas to remove any excess diazomethane and the resulting solution was concentrated to give 1-diazo-3,3-dimethyl-2-butanone as a yellow oil which was used directly in the next step. After addition to warm slowly overnight to room temperature The solution was purged with a flow of nitrogen gas to remove any excess diazomethane the resulting solution was concentrated

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of 2 mL (2.3 g, 16 mmol) of boron trifluoride etherate in 20 mL of chloroacetonitrile at 0° C. was added a solution of 1.33 g (10 mmol) of 1-diazo-3,3-dimethyl-2-butanone in 5 mL of chloroacetonitrile dropwise. The resulting solution was stirred at 0° C. for 0.5 h. The reaction mixture was added to saturated aqueous sodium bicarbonate solution to neutralize the acid and the product was extracted three times with dichloromethane. The combined extracts was dried (sodium sulfate), concentrated and purified by flash column chromatography (Merck silic a, 25×200 mm, dichloromethane) to give 1.1 g of 2-(chloromethyl)-5-t-butyloxazole as a yellow liquid (6.4 mmol, 64% overall from the acid chloride). 1H NMR δ (CDCl3): 1.30 (s, 9 H), 4.58 (s, 2 H), 6.68 (s, 1 H); MS 174 (M+H)+ ; TLC: Rf (silica gel, dichloromethane)=0.33; the product was extracted three times with dichloromethane The combined extracts was dried (sodium sulfate) concentrated purified by flash column chromatography (Merck silic a, 25×200 mm, dichloromethane)