反应详情

A mixture of 1.08 g of 2-methyl-6-chloro-1,3-benzthiazine 1.51 g of 3-formylbenzyl alcohol t-butyldimethylsilyl ether and 5 drops of piperidine in 60 ml of benzene was heated to reflux in a Dean-Stark trap for 1 hour. An additional 5 drops of piperidine were added and the refluxing continued from 30 hours. The mixture was diluted with 400 ml of ethyl acetate and washed with water (1×40 ml) and brine (1×40 ml). The organic layer was dried over magnesium sulfate and concentrated to 2 g of crude product which was chromatographed on silica gel using 5% ethyl acetate in hexane (v:v), 188 mg, m.p. 58°-60° C.

1. temperaturewas heated
2. temperatureto reflux in a Dean-Stark trap for 1 hour
3. washwashed with water (1×40 ml) and brine (1×40 ml)
4. dry with materialThe organic layer was dried over magnesium sulfate
5. concentrationconcentrated to 2 g of crude product which
6. customwas chromatographed on silica gel using 5% ethyl acetate in hexane (v:v), 188 mg, m.p. 58°-60° C.