Synthesis of novel intermediate(s) for preparing rivastigmine
AssigneeCadila Corporate Campus
InventorsJhillu Singh Yadav, Gyanchander Eppa, Pranav Rameshbhai Vachharajani, Nutan Bharatbhai Vekariya, Chetan Umeshbhai Bhavsar, Rajiv Indravadan Modi, Bakulesh Mafatlal Khamar
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Abstract
The present invention relates to novel intermediate(s), which are useful for the preparation of Rivastigmine compound of formula (I) and its pharmaceutically acceptable salts. The present invention further relates to the processes for the preparation of such novel intermediate(s) and preparation of Rivastigmine using such novel intermediate(s).
Claims8
A process for the preparation of compound of formula (V)
- wherein R1 represent C1-C3 alkyl or
- comprising the steps of:
- a) reacting a compound of formula (II) with phthalic anhydride to obtain a compound of formula (III);
- b) reacting the compound of formula (III) with a chiral resolving agent of formula (VI) to obtain a compound of formula (IV);
- wherein * is a stereogenic center;
- R2, R3 and R4 are selected from hydrogen, C1-4 alkyl, C6-10 aryl and C7-12 alkylaryl, wherein R3 and R4 are different;
- and
- c) desaltification of the compound of formula (IV) followed by ester hydrolysis to obtain formula (V).
A compound of formula (III) and its salts
- wherein R1 wherein R1 represent C1-C3 alkyl or
A process for the preparation of Rivastigmine of formula (I) or its pharmaceutically acceptable salts comprising the steps of:
- a) reacting a compound of formula (II) with phthalic anhydride to obtain a compound of formula (III);
- b) reacting the compound of formula (III) with a chiral resolving agent of formula (VI) to obtain a compound of formula (IV);
- desaltification of the compound of formula (IV) followed by ester hydrolysis to obtain formula (V);
- wherein R1 of formula (V) is C1-C3 alkyl then the compound of formula (V) under goes amidation and converting the methoxy on phenyl to hydroxyl before final conversion to Rivastigmine of formula (I) or its pharmaceutical acceptable salt;
- or
- R1 of formula (V) is
- then compound of formula (V) directly under goes amidation to obtain Rivastigmine of formula (I) or its pharmaceutical acceptable salt.
Dependencies are inferred from the claim text.