Triethylamine → tert-Butyl 3-(methylcarbamoyl)pentan-3-ylcarbamate

Participants

Reaction Steps

A mixture of 2-(tert-butoxycarbonylamino)-2-ethylbutanoic acid (Example 45a, 400 mg, 2 mmol), HBTU (CAN 94790-37-1, 1.3 g, 3 mmol), triethylamine (0.7 g, 7 mmol) in DMF (10 mL) was stirred for 30 min, then methanamine hydrochloride (CAN 593-51-1, 260 mg, 6 mmol) was added into the mixture and the solution was stirred overnight. After that, the solution was diluted with water (20 mL) and extracted with ethyl acetate (3×30 mL), the combined organic layer was washed with water (3×50 mL) and brine (60 mL), then evaporated to dryness. The crude product (0.18 g, 45%) obtained as a light yellow solid was used for the next step directly without any purification.

Provenance & Evidence