Triethylamine → 3-(N-tert-Butoxylcarbonyl-N-methylamino)phenyl isocyanate

Participants

Reaction Steps

Et3N (3.71 g, 36.7 mmol) and a solution of ethyl chloroformate (4.31 g, 39.7 mmol) in acetone (10 ml) were successively added dropwise to a solution of 3-(N-tert-butoxylcarbonyl-N-methylamino)benzoic acid (8.0 g, 31.8 mmol) in acetone (64 ml) below 5° C. After stirring for 30 min, a solution of NaN3 (3.10 g, 47.7 mmol) in water (10 ml) was added to the solution below 5° C. The mixture was stirred at the same temperature for a further 1 h, then poured into toluene (80 ml) and water (160 ml). The organic portion was washed with brine, refluxed for 2 h and evaporated. The residue was distilled (100°-105° C./0.9-1.0 mmHg) to afford the title compound (6.2 g, 78%) as a yellow oil.

Provenance & Evidence