Process for the preparation of adefovir dipivoxil
OwnerSiva Rama Prasad VELLENKI, Madhu Murthy Nadella +3inventors
InventorsSiva Rama Prasad VELLENKI, Madhu Murthy Nadella, Rajendar Reddy Mullamalla, Venkata Siva Reddy Arumalla, Ravindra Pulyala
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Abstract
An improved process for the preparation of adefovir dipivoxil and its pharmaceutically acceptable salts or solvates comprises the condensation of adefovir with chloro methyl pivalate in a mixture of two or more solvents in the presence of a base and isolating the resulting adefovir dipivoxil.
Claims15
A process for the preparation of adefovir dipivoxil, comprising the steps of:
- a) condensing (2-(6-amino-9H-purin-9-yl)ethoxy)methylphosphonic acid (adefovir) with chloro methyl pivalate in a mixture of two or more solvents in the presence of a base;
- and
- b) isolating adefovir dipivoxil.
An improved process for the preparation of (2-(6-amino-9H-purin-9-yl)ethoxy)methylphosphonic acid (adefovir) comprising the steps of:
- a) dealkylating dialkyl (2-(6-amino-9H-purin-9-1)ethoxy)methylphosphonate with a mineral acid;
- and
- b) isolating adefovir.
A process for the preparation of adefovir dipivoxil formic acid solvate comprising the steps of:
- c) dissolving adefovir dipivoxil in an ester solvent;
- d) adding formic acid to the obtained solution;
- and
- e) isolating adefovir dipivoxil formic acid solvate.
Dependencies are inferred from the claim text.