Continuous Reaction/Crystallization Process for Production of a Hazardous Intermediate

Perchloric acid appears unique in its ability to catalyze stereoselective trans-acetalizations of steroids. However, the requisite recipes result in an intermediate phase enriched in perchlorate and organic material with the potential for catastrophic decomposition. We present here a discussion of the relevant chemistry and the engineering of a continuous reactor/crystallizer/quench for the safe production of a candidate for asthma and irritable bowel syndrome.