4-Methylmorpholine → Methyl 3-methyl-2-(4-(4-nitrophenyl)thiazole-2-carboxamido)butanoate

Participants

Reaction Conditions

Reaction Steps

N-methyl morpholine (1.8 gm) was added to a solution of 4-(4-nitrophenyl)thiazole-2-carboxylic acid (Intermediate 3, step B, 4.5 gm) in THF (300 ml). The reaction mixture was stirred for 5 minutes and then cooled to −20° C. Isobutyl chloroformate (2.45 gm) was added to it and the reaction mixture was stirred for 20 minutes. To it was added L-valine methyl ester hydrochloride (7.2 gm) previously neutralized with triethylamine (4.63 gm) and the reaction mass was stirred for 3 hours as the temperature rose to RT. Organic solvent was concentrated and compound was purified by column chromatography (silica gel, EtOAc-petroleum ether) to obtain yellow solid as title compound. Yield: 4.4 gm (67%). 1H NMR (DMSO-d6, 300 MHz): δ 8.36 (d, 2H), 8.14 (d, 2H), 7.94 (s, 1H), 7.80 (d, 1H), 4.77 (t, 1H), 3.83 (s, 3H), 2.37 (m, 1H), 1.071 (s, 6H).

Provenance & Evidence