| US 7,547,785 B2 | ||
| Process for preparing topotecan | ||
| Venkata Raghavendra Acharyulu Palle, Hyderabad (India); Sekhar Munaswamy Nariyam, Hyderabad (India); and Lankeshwara Rao Matti, Hyderabad (India) | ||
| Assigned to Dr. Reddy's Laboratories Limited, Hyderabad (India); and Dr. Reddy's Laboratories, Inc., Bridgewater, N.J. (US) | ||
| Filed on Dec. 19, 2006, as Appl. No. 11/612,558. | ||
| Claims priority of provisional application 60/747881, filed on May 22, 2006. | ||
| Claims priority of application No. 1919/CHE/2005 (IN), filed on Dec. 26, 2005. | ||
| Prior Publication US 2007/0149783 A1, Jun. 28, 2007 | ||
| Int. Cl. C07D 491/22 (2006.01); C07D 491/147 (2006.01) | ||
| U.S. Cl. 546—48 [546/47] | 28 Claims |
| 1. A process for preparing topotecan or a salt thereof, comprising the steps of:
hydrogenating camptothecin in the presence of a hydrogenation catalyst and thioanisole to form 10-hydroxycamptothecin; and
reacting 10-hydroxy camptothecin with dimethylamine and about 1 to about 3 equivalents of formaldehyde, per equivalent of
10-hydroxy camptothecin, in the presence of acetic acid to form topotecan acetate.
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