tert-butyl N-(3-chloro-2-methylphenyl)carbamate

反应条件: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a cold solution of (3-Chloro-2-methyl-phenyl)-carbamic acid tert-butyl ester (5.0 g, 20.7 mmol) in anhydrous tetrahydrofuran (100 ml) at −40° C. under N2, was added a solution of s-butyl lithium (40 ml, 52 mmol, 1.3 M in cyclohexane) dropwise and maintained the reaction temperature below −30° C. To the bright yellow solution at −50° C. was added a solution of N-methoxy N-methylacetamide (2.33 g, 22.6 mmol) in anhydrous tetrahydrofuran (40 ml) dropwise and maintained the reaction temperature between −50° C. to −40° C. The mixture was allowed to warm to −10° C. over a period of 35 minutes and was then partitioned between diethyl ether and 0.3 N hydrochloric acid solution. The organic extract was washed with water and brine, dried (anhydrous sodium sulfate), and concentrated under reduced pressure. The residue was purified by flash column chromatography over silica gel eluting with 20% ethyl acetate in hexane to give crude [3-Chloro-2-(2-oxo-propyl)-phenyl]-carbamic acid tert-butyl ester (5.21 g) as a colorless oil. maintained the reaction temperature below −30° C maintained the reaction temperature between −50° C. to −40° C was then partitioned between diethyl ether and 0.3 N hydrochloric acid solution The organic extract was washed with water and brine dried (anhydrous sodium sulfate) concentrated under reduced pressure The residue was purified by flash column chromatography over silica gel eluting with 20% ethyl acetate in hexane

反应条件: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a cold solution of (3-Chloro-2-methyl-phenyl)-carbamic acid tert-butyl ester (5.0 g, 20.7 mmol) in anhydrous tetrahydrofuran (100 ml) at −40° C. under N2, was added a solution of s-butyl lithium (40 ml, 52 mmol, 1.3 M in cyclohexane) dropwise and maintained the reaction temperature below −30° C. To the bright yellow solution at −50° C. was added a solution of N-methoxy N-methylacetamide (2.33 g, 22.6 mmol) in anhydrous tetrahydrofuran (40 ml) dropwise and maintained the reaction temperature between −50° C. to −40° C. The mixture was allowed to warm to −10° C. over a period of 35 minutes and was then partitioned between diethyl ether and 0.3 N hydrochloric acid solution. The organic extract was washed with water and brine, dried (anhydrous sodium sulfate), and concentrated under reduced pressure. The residue was purified by flash column chromatography over silica gel eluting with 20% ethyl acetate in hexane to give crude [3-Chloro-2-(2-oxo-propyl)-phenyl]-carbamic acid tert-butyl ester (5.21 g) as a colorless oil. maintained the reaction temperature below −30° C maintained the reaction temperature between −50° C. to −40° C was then partitioned between diethyl ether and 0.3 N hydrochloric acid solution The organic extract was washed with water and brine dried (anhydrous sodium sulfate) concentrated under reduced pressure The residue was purified by flash column chromatography over silica gel eluting with 20% ethyl acetate in hexane