| 摘要 |
<p>A process for preparing a compound of formula (I), or salt thereon wherein X is CH2, O or a protected keto group, R is H, CH3, acetyl or a silyl protecting group comprises reacting a compound of formula (II) with a -chloroethyl chloroformate and hydrolysing the resulting intermediate. In particular, R is CH3 and X is O and the process is therefore the preparation of noroxycodone from oxycodone. The reaction is preferably carried out in an aprotic solvent, e.g. dichloromethane or acetonitrile, in the presence of a proton acceptor, e.g. carbonate or bicarbonate. The intermediate may not be isolated prior to hydrolysis and the hydrolysis step may be performed with aqueous acid or aqueous tetrahydrofuran.</p> |
