US 2024/0228425 A1 · PREPARATION METHOD OF PILOCARPINE AND ITS INTERMEDIATE COMPOUNDS

Abstract

The invention relates to a process for preparing pilocarpine and intermediate compounds therefor. In particular, the present invention relates to key intermediates for the preparation of pilocarpine, i.e., compounds of formula I and formula II, and processes for their preparation. One method is to use malic acid as a raw material, react it with alcohol or sulfate ester first, then react with haloethane, etc. to obtain the compound of formula II, and finally react with a halogenating reagent to obtain the compound of formula I; in the other method, n-butyraldehyde is used as a raw material, and is subjected to condensation reaction, oxidation reaction, esterification reaction and sulfonylation reaction in sequence to obtain the compound of formula II, and finally react with a halogenating reagent to obtain the compound of formula I. The preparation method of the present invention has the advantages of mild reaction conditions, simple reaction process, high overall yield and high purity of the target product, and is therefore very suitable for industrial production.

Claims20

Dependent claims

A compound of formula II:

wherein R3 is —S(O)2—Rx and Rx is C1-8alkyl, C3-8cycloalkyl, C6-10aryl, or C6-10aryl-C1-8alkyl, each of which is optionally substituted with one or more substituents selected from the group consisting of C1-8alkyl, C1-8alkoxy, haloC1-8alkyl, halogen and nitro, and
R1 and R2 may be the same or different, and are each independently selected from the group consisting of C1-8alkyl, C3-8cycloalkyl, C6-10aryl, or C6-10aryl-C1-8alkyl, wherein said C1-8alkyl, C3-8cycloalkyl, C6-10aryl, or C6-10aryl-C1-8alkyl are each optionally substituted with one or more of C1-8alkyl, C1-8alkoxy, haloC1-8alkyl, haloC1-8alkoxy, halogen, hydroxy, and nitro,
preferably, R1 and R2 are each independently selected from the group consisting of C1-8alkyl, benzyl, C1-8alkyl substituted benzyl, C1-8alkoxy substituted benzyl or halogen substituted benzyl.

Dependencies are inferred from the claim text.

Preparation method of pilocarpine and its intermediate compounds

Life of this patent

Preparation method of pilocarpine and its intermediate compounds

Life of this patent

Abstract

Claims20