Synthesis of 14C-labelled EM-800 (SCH 57050) and EM-652·HCl (SCH 57068·HCl, acolbifene), pure selective estrogen receptor modulators
✍ Scribed by Jean-Yves Sancéau; Fernand Labrie; Sylvain Gauthier
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- French
- Weight
- 166 KB
- Volume
- 47
- Category
- Article
- ISSN
- 0022-2135
- DOI
- 10.1002/jlcr.862
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✦ Synopsis
Abstract
EM‐800 (SCH 57050) and EM‐652·HCl (SCH 57068·HCl, acolbifene) are orally active pure selective estrogen receptor modulators. The corresponding ^14^C~2~‐radiolabelled compounds 1 and 2 were synthesized for metabolic studies with uniform labelling of two carbons within the benzene ring of the 2H‐1‐benzopyran moiety by optical resolution of racemic (±)‐[^14^C~2~]EM‐343 4. This pivotal intermediate amine was prepared in 6 steps with 38% yield from commercially available [U‐^14^C~2~]resorcinol (3). Resolution by selective crystallization of the diastereomeric mixture of (S)‐(+)‐camphorsulfonates salts gave the desired (+)‐[^14^C~2~]EM‐652·(+)‐CSA 13. Moreover, the racemic amine 4 was recovered from mother liquors by basic treatment, and resolved again. We obtained salt 13, at a 52% yield with 97% diastereomeric excess by repeating the resolution–racemization process. Finally, the corresponding dipivaloate (+)‐[^14^C~2~]EM‐800 1 and hydrochloride salt (+)‐[^14^C~2~]EM‐652·HCl 2 were prepared at respective specific activities of 19.7 and 24.5 µCi/mg with 96.3% radiochemical purity. Copyright © 2004 John Wiley & Sons, Ltd.