4-Methylmorpholine → HCID 13877874, compound

Participants

Reaction Steps

A solution of 150 g of S-[2-amino-1-(2-thienyl)ethyl]-N-t-butoxycarbonyl-L-cysteine [prepared as described in step (b) above] and 52 ml of N-methylmorpholine in 1 liter of dimethylformamide was added to a solution of 108.4 ml of diphenylphosphoryl azide in 500 ml of dimethylformamide at 10° C., over a period of 4 hours, and the mixture was left to stand at room temperature overnight. At the end of this time, 1.5 liters of ethyl acetate and 1.5 liters of water were added, and the organic layer was separated. The aqueous layer was extracted twice with ethyl acetate, and the resulting extracts were combined with the separated organic layer. The resulting organic mixture was washed twice, each time with an aqueous solution of sodium chloride, and then dried over anhydrous magnesium sulfate, after which the solvent was evaporated off. The residue was subjected to silica gel column chromatography, using a 1:4 by volume mixture of ethyl acetate and methylene chloride as eluent, to give 112.5 g of the title compound as a gummy substance.

Provenance & Evidence