Citric Acid → tert-Butyl (4-ethynyl-2-nitrophenyl)carbamate

Participants

Reaction Steps

To a solution of (2-nitro-4-trimethylsilanylethynyl-phenyl)-carbamic acid tert.-butyl ester (Example F1) (3.54 g, 10.6 mmol) in MeOH (10 mL) and THF (20 mL) at 0° C. was added 1N NaOH (13 mL) and stirring was continued at 23° C. for 30 min. Poured into cold 5% citric acid, extracted with EtOAc (300 mL), washed with sat. NaHCO3-sol. and brine, dried over MgSO4. Removal of the solvent in vacuum left a dark brown oil, which was purified by silica gel column chromatography with hexane/EtOAc 19:1. Obtained as a yellow solid (2.4 g).

Provenance & Evidence