Reaction of L-2-acetylamino-2-carbomethoxyethanesulfonyl chloride with ammonia.

The conversion of L-2-acetylamino-2-carbomethoxyethanesulfonyl chloride (I) to L-2-acetylamino-2-carbomethoxyethanesulfonamide (II) proceeds with considerable variability in yield We therefore investigated the nature of the by-product (s) of this reaction in order to prepare II in consistently high yields and with reproducible physical data. Compound II [m. p. 145°, [a] 54 2 8 ° (c 2, 95% ethanol), [ajc1—30° (c 2, water); characteristic absorption bands in the infrared spectrum are located at 3360, 3270, 1725, 1650, and 1320 c m 1 ] 1 ' 2 was obtained in 75% yield (crystallized from water/methanol) when I (12 g) was treated in benzene with dry ammonia for not longer than 4 minutes. In addition, product II had to be removed from the benzene solution immediately upon termination of the reaction. An