Trimethylsilyldiazomethane → Methyl 4-(4-aminophenyl)-4-oxobutanoate

Participants

Reaction Steps

To a stirred, partial solution of 4-(4-amino-phenyl)-4-oxo-butyric acid (6.96 g, 0.0360 mol) in toluene (240 mL) and methanol (240 mL) at room temperature under nitrogen was added dropwise over 30 minutes a 2.0 M solution of trimethylsilyldiazomethane in hexanes (18 mL, 0.036 mol), and the mixture was stirred for 22 hours. Additional 2.0 M solution of trimethylsilyldiazomethane in hexanes (12 mL, 0.024 mol) was added dropwise, and the mixture was stirred overnight. Additional 2.0 M solution of trimethylsilyldiazomethane in hexanes (19 mL, 0.038 mol) was added dropwise, and the mixture was stirred overnight. After a total of 3 days, the mixture was rotary evaporated, and the residue was suspended in tetrahydrofuran (200 mL) and dichloromethane (100 mL). The mixture was washed with 0.1 M aqueous sodium hydroxide, water, brine, and dried (Na2SO4). The solution was rotary evaporated to give a solid, which was crystallized from chloroform to give 5.13 g of 4-(4-amino-phenyl)-4-oxo-butyric acid, methyl ester as a tan solid; mp 160-162° C.

Provenance & Evidence