Tert-Butylamine → N-(tert-butylcarbamothioyl)benzamide

Participants

Reaction Steps

N-Benzoyl-N'-(t-butyl)carbodiimide was prepared by the method of O. Misunobu et al (Bull. Chem. Soc. Japan, 45, p. 3607, 1972) in two steps from t-butylamine, benzoyl isothiocyanate, diethylazodicarboxylate and triphenylphosphine. The initial reaction combined equimolar amounts (0.04 m) of benzoyl isothiocyanate and t-butylamine in 125 ml of dry acetone. After two hours at ambient temperature and 0.5 hour at 40° C., the solution was evaporated to dryness and the precipitate washed with petroleum ether and recrystallized from acetonitrile to yield N-benzoyl-N'-(t-butyl)thiourea (52%), mp 128.5°-130° C. To this was added an equivalent of diethylazodicarboxylate in 100 ml of tetrahydrofuran, and the solution was allowed to stir three days. After the addition of triphenylphosphine the solution stirred an additional ten days, the solvent was evaporated and the residue was extracted with petroleum ether, dried over sodium sulfate and then distilled to yield 38% of N-benzoyl-N'-(t-butyl)carbodiimide, bp 94 (0.04 torr), lit. bp 110° C. (0.55 m).

Provenance & Evidence