Methanol → 4-Bromo-2,7-dimethoxy-3H-phenothiazin-3-one

Participants

Reaction Steps

A solution of bromine (280 g) in acetic acid (2.8 l) was added over a period of 30 minutes to a suspension of 2,7-dimethoxy-3H-phenothiazin-3-one (250 g) (Step 3) in acetic acid (7.5 l) and the mixture was stirred for 2 hours. Methanol (12 l) was added over a period of 30 minutes to the reacting mixture and the black suspension was stirred until it became an orange suspension. Then, the precipitate was filtered, washed with methanol and air-dried to afford the desired compound (312 g), m.p. 260°-261° C.

Provenance & Evidence