Dimethylcarbamoyl Chloride → HCID 68725513, compound

Participants

Reaction Steps

(S)-3-(4-Benzyloxy-3-hydroxy-phenyl)-2-tert-butoxycarbonylamino-propionic acid methyl ester (401 mg) was dissolved in dichloromethane (8 ml) and N,N-dimethylcarbamoyl chloride (0.092 ml, leg) added. Triethylamine (0.14 ml, 1 eq) was added and the mixture was stirred and heated under reflux. The reaction was monitored by HPLC/MS and further portions of N,N-dimethylcarbamoyl chloride and triethylamine were added in order to complete the reaction. After a total of 8 hours reflux the reaction mixture was evaporated to dryness and absorbed onto silica gel. Chromatography, eluting with mixtures of ethyl acetate-hexane afforded (S)-3-(4-Benzyloxy-3-dimethylcarbamoyloxy-phenyl)-2-tert-butoxycarbonylamino-propionic acid methyl ester as an oil, 315 mg; Rf 0.14 (ethyl acetate-hexane 1:3); HPLC/MS retention time 3.89 min, m/z 473 (MH+). Crystallisation from ethyl acetate-hexane gave (S)-3-(4-benzyloxy-3-dimethylcarbamoyloxy-phenyl)-2-tert-butoxycarbonyl-amino-propionic acid methyl ester as a white solid, 126 mg; NMR (500 MHz, CDCl3) 1.42 (9H, s), 2.95 (3H, s), 2.98-3.04 (5H, m), 3.70 (3H, s), 4.52-4.54 (ca 1H, m), 4.97-5.00 (ca 1H, br d), 5.05 (2H, s), 6.88-6.92 (3H, m), 7.28-7.40 (5H, m).

Provenance & Evidence