4-(4,4-Dimethoxybutyl)-5-oxo-[1,4]diazepane-1-carboxylic acid tert-butyl ester → 5-Oxo-4-(4-oxobutyl)-[1,4]diazepane-1-carboxylic acid tert-butyl ester

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Reaction Steps

A solution of 4-(4,4-dimethoxybutyl)-5-oxo-[1,4]diazepane-1-carboxylic acid tert-butyl ester (3 g, 9.08 mmole) in glacial acetic acid containing 0.5 mL water (10 mL) was stirred at room temperature for 24 hours. The solution was concentrated at 35° C. under reduced pressure, and the residue was partitioned between saturated aqueous sodium bicarbonate and diethyl ether. The organic phase was dried (magnesium sulfate), concentrated, and the residue recrystallized from diethyl ether/hexane to give 5-oxo-4-(4-oxobutyl)-[1,4]diazepane-1-carboxylic acid tert-butyl ester (0.85 g,), m.p. 86-87° C.

Provenance & Evidence