Paul A Mckenzie

US Patent:

55853838, Dec 17, 1996

Filed:

May 3, 1995

Appl. No.:

8/434082

Inventors:

Andrew L. Forman - Scotch Plains NJ
Sean R. Holihan - Dayton NJ
Guy R. Humphrey - Belle Mead NJ
David M. Lashen - Edison NJ
James A. McCauley - Belle Mead NJ
Paul F. McKenzie - Yardley PA
Ross A. Miller - Fanwood NJ
Pascal H. Toma - Piscataway NJ

Assignee:

Merck & Co., Inc. - Rahway NJ

International Classification:

C07S 7300
A61K 3158

US Classification:

514284

Abstract:

By this invention, there is provided a process for producing crystalline 4,7. beta. -dimethyl-4-aza-5. alpha. -cholestan-3-one of structural formula (I) from 4,7. beta. -dimethyl-4-aza-5. alpha. -cholestan-3-one oil. ##STR1## This crystallization process of the present invention comprises crystallization of the oil optionally containing residual solvent with vigorous but controlled agitation. Preferably, this crystallization process is carried out at select and controlled temperatures. Further, 4,7. beta. -dimethyl-4-aza-5. alpha. -cholestan-3-one has been found to exist in at least two novel polymorphic nonsolvated forms, herein referred to as Form I and Form II. Form I can be prepared pure by careful control of the crystallization process.