Preparation of polymorphs of motildes.

Abstract

Polymorphs of motilides are prepd. A motilide was repeatedly dissolved in dichloromethane and subjected to four rotary evaporator cycles and then dried under high vacuum. It was then lyophilized from acetonitrile-water (1:1 vol./vol.), dried in a vacuum oven (16 h, 50 °C) to give the polymorph I (m.p. 106-108 °C by capillary m.p. app.). [on SciFinder(R)]