Diazomethane → Ethyl 2-(3,5-difluoro-4-hydroxyphenyl)cyclopropanecarboxylate

Participants

Reaction Conditions

Reaction Steps

Into a 100-mL round-bottom flask, was placed a solution of 3-methyl-1-nitro-3-nitrosoguanidine (1.25 g, 8.50 mmol, 6.80 equiv) in ether (19 mL). This was followed by the addition of a solution of potassium hydroxide (1.57 g, 27.98 mmol, 22.40 equiv) in water (2.5 mL) dropwise with stirring at 0° C. the mixture were stirred at 0 degree for 2 min, the diazomethane was made. The ether phase was separated and dried over anhydrous sodium sulfate. Then it was used for the reaction directly. 100-mL round-bottom flask, was placed ethyl (2E)-3-(3,5-difluoro-4-hydroxyphenyl)prop-2-enoate (285 mg, 1.25 mmol, 1.00 equiv), Pd(OAc)2 (47 mg, 0.21 mmol, 0.17 equiv), ether (12 mL). The mixture was cooled to 0 degree C., the ether solution of diazomethane which got above was added dropwise with stirring at 0° C. The resulting solution was stirred overnight at 0° C. in a water/ice bath. The reaction was then quenched by the addition of acetic acid. The resulting mixture was concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (30/70). The collected fractions were combined and concentrated under vacuum. This resulted in 130 mg (39%) of ethyl 2-(3,5-difluoro-4-hydroxyphenyl)cyclopropane-1-carboxylate as colorless oil. Mass spectrum (ESI, m/z): Calcd. for C12H12F2O3, 243.1 (M+H). found 243.1

Provenance & Evidence