Abstract: Methods for providing a carboxamide compound and intermediates used in the preparation of the carboxamide compound are provided. The methods include reacting 5-[3-(3-hydroxyphenoxy)azetidin-1-yl]-5-methyl-2,2-diphenylhexanenitrile benzoate with a reagent and hydrochloric acid to form the carboxamide compound including 5-[3-(3-hydroxyphenoxy)azetidin-1-yl]-5-methyl-2,2-diphenylhexanamide hydrochloride.

Abstract: The present invention relates to an improved process for the preparation of Tenofovir Disoproxil and its pharmaceutically acceptable salts comprising the steps of: a) esterifying Tenofovir with chloromethyl isopropyl carbonate in presence of a base, phase transfer catalyst and optionally dehydrating agent, in a suitable solvent; b) optionally purifying Tenofovir Disoproxil; and c) converting of Tenofovir Disoproxil into its pharmaceutically acceptable salts. The present invention further relates to a process for the preparation of Tenofovir by reacting 1-(6-amino-purin-9-yl)-propan-2-ol with toluene-4-sulfonic acid diethoxy phosphoryl methyl ester in presence of a base in a non-polar solvent medium followed by hydrolysis.

Abstract: The present invention relates to an improved process for the preparation of Tenofovir Disoproxil and its pharmaceutically acceptable salts comprising the steps of: a) esterifying Tenofovir with chloromethyl isopropyl carbonate in presence of a base, phase transfer catalyst and optionally dehydrating agent, in a suitable solvent; b) optionally purifying Tenofovir Disoproxil; and c) converting of Tenofovir Disoproxil into its pharmaceutically acceptable salts. The present invention further relates to a process for the preparation of Tenofovir by reacting 1-(6-amino-purin-9-yl)-propan-2-ol with toluene-4-sulfonic acid diethoxy phosphoryl methyl ester in presence of a base in a non-polar solvent medium followed by hydrolysis.

Abstract: The present invention relates to an improved process for the preparation of cis-nucleoside derivative of formula-1 involving chlorination of the compound of formula-2 followed by reaction with compound of formula-3 in presence of a base to get compound of formula-4, reacting the compound of formula-4 with an alkyl halide (RiX) to get a quaternary ammonium salt then with cytosine derivative of formula-5 to provide the compound of formula-6, optionally de-protecting the compound of formula-6 to the compound of formula-7, reducing compound of formula-7 with metal catalyst in presence of a buffer solution, then adding an organic acid to get the compound of formula-8, and converting the compound of formula-8 to cis-nucleoside derivative of formula-1. The present invention further relates to novel cis-nucleoside derivative of formula-8. The present invention also relates to a pharmaceutical composition comprising cis-nucleoside derivative of formula-1 with excipients.