| 摘要 |
<p>PURPOSE:To prepare an alpha-chlorinated carbonic acid ester useful as a raw material for drugs such as semisynthetic penicillin, etc. by simple operations in high selectivity, by reacting a specific chloroformate with an aldehyde. CONSTITUTION:An aldehyde (e.g., acetaldehyde, etc.) shown by the formula I (R<1> is 1-5C alkyl is reacted with a chloroformate (e.g., isopropylchloroformate, etc.) shown by the formula II (R<2> is 1-5C alkyl) in the presence of a catalyst (preferably tertiary heterocyclic amine such as pyridine, etc.) to given an alpha- chlorinated carbonic acid ester shown by the formula III. The chloroformate shown by the formula II is easily obtainable by blending and reacting a corresponding alcohol with phosgene at <=20 deg.C low temperature.</p> |
