Diisopropylethylamine → (S)-4-tert-butoxycarbonylamino-4-[4-(N-hydroxycarbamimidoyl)-benzyl carbamoyl]-butyric acid benzyl ester

Participants

Reaction Steps

A solution of compound Q (9.65 g, 20.0 mmol), hydroxylamine hydrochloride (2.10 g, 30.0 mmol) and DIEA (5.22 ml, 30.0 mmol) in ethanol (abs., 150 ml) was refluxed for 6 h. The reaction mixture was allowed to cool to room temperature and stirred for additional 16 h, then the solvents were evaporated in vacuo. The resultant residue was dried in vacuo to provide compound R (14.8 g, yield exceeded quantitative) as yellowish oil. LC-MS [M+H] 485.5 (C25H32N4O6+H, calc: 485.8). Compound R was used without further purification.

Provenance & Evidence