Patent ID: 11958858
Assignee: ZHEJIANG AUSUN PHARMACEUTICAL CO., LTD.
Field: Organic fine chemistry (Chemistry)
Classification: CPC C | IPC C

Claim 2:
3. The method according to claim 1, for preparing Asenapine of formula I,, characterized in that the method comprises the following steps:
(a-1) Intermediate II is subjected to internal nucleophilic substitution under basic condition to give cyclic ether Intermediate III,, wherein X is F, Cl, Br or I,
wherein the base is an alkali metal hydroxide, alkali metal carbonate, alkali metal bicarbonate, metal hydride, organometallic compounds or non-nucleophilic organic strong based;

(a-2) the nitro group of intermediate III is reduced to obtain intermediate IV,, (a-3) Intermediate IV is subjected to a diazotization deamination reaction, and then purified by recrystallization to obtain pure product Asenapine of formula I,,