1-chloroethyl chloroformate is a kind of efficient and mild reagent for debenzylation, especially for compounds with easily reducible functional groups, the use of this reagent will not affect other functional groups in the molecule; It can also be used to remove the alkyl group on the tertiary amine, and the carbamate obtained can be heated in methanol to remove the carbamate group and obtain the secondary amine with high yield; In pharmaceutical synthesis, it is used for cefpodoxime proxetil, candesartan proxetil, cefotiam proxetil, Bacillin, ampicillin, etc.