BigPatents India

An improved process for the preparation of sulfamate derivatives such as topiramate is provided comprising (a) reacting an alcohol with sulfuryl chloride in the presence of an amine base and in a first halogenated hydrocarbon solvent selected from the group consisting of aliphatic halogenated hydrocarbon solvents having 1 to 12 carbon atoms and at least three halogen atoms, aliphatic halogenated hydrocarbon solvents having 2 to 12 carbon atoms and less than three halogen aatoms, aromatic halogenated hydrocarbon solvents having 6 to 18 carbon atoms and mixtures thereof to produce a chlorosulfate intermediate and (b) reacting the chlorosulfate intermediate with an amine of the formula R1NH2, wherein R1 is hydrogen or an alkyl from 1 to 4 carbon atoms, in a second halogenated hydrocarbon solvent selected from the group consisting of aliphatic halogenated hydrocarbon solvents having 1 to 12 carbon atoms and at least three halogen atoms, aliphatic halogenated hydrocarbon solvents having 2 to 12 carbon atoms and less than three halogen atoms, aromatic halogenated hydrocarbon solvents having 6 to 18 carbon atoms and mixtures thereof. Drawing: NIL Total Pages: 32 Fig. Nil