Sodium Azide → 3-Aminorifamycin S

Participants

Reaction Steps

3-amino-4-deoxo-4-imino-rifamycin S, (a) above, is described in U.S. Pat. No. 4,017,481, where it is made by reacting 3-amino-rifamycin S with gaseous ammonia. The reaction is carried out in a solution of tetrahydrofuran at room temperature for 15 hours with further addition of ammonia. The starting material, 3-amino-rifamycin S may obtained as described in U.S. Pat. No. 4,007,169, where it is obtained by reacting sodium azide with rifamycin S. The reaction is carried out in methylformamide at 35° C. for 60 minutes. The reaction mixture is diluted with methylene chloride and washed with water. The aqueous phase contains rifamycin SV which may be oxidized by, for example, nitrous acid to the starting material rifamycin S. The organic phase is washed with water, dried with sodium sulphate and evaporated to yield 3-amino rifamycin S which is recrystallized from 2-methoxy ethanol.

Provenance & Evidence