反应详情

A solution of 4-(5-chloro-2-methoxy-phenyl)-4-methoxy-piperidine-1-carboxylic acid tert-butyl ester 5c (3.8 g, crude from last step) in methanol/HCl (2 M, 50 mL) was stirred at room temperature for 4 h, then the mixture was concentrated to half of volume under 40° C. and then ether was added. The precipitated was filtered and washed with ether to obtain 4-(5-chloro-2-methoxyphenyl)-4-methoxypiperidine 5d as its HCl salt. 1H NMR (DMSO-d6): δ 8.95 (b, 2H), 7.37-7.34 (q, J1=8.8 Hz, J2=8.8 Hz, 1H), 7.21-7.20 (d, J=2.8 Hz, 1H), 7.09-7.07 (d, J=8.8 Hz, 1H), 3.78 (s, 3H), 3.16-3.13 (m, 2H), 3.13-2.98 (m, 5H), 2.35-2.28 (m, 2H), 2.19-2.16 (m, 2H). ESI-MS m/z 256.8.

1. concentrationthe mixture was concentrated to half of volume under 40° C.
2. additionether was added
3. filtrationThe precipitated was filtered
4. washwashed with ether