Process for preparing dorzolamide

Abstract

There is provided a process for preparing dorzolamide and processes for preparing intermediates useful in the preparation of dorzolamide. In particular, there is provided a process for preparing an acetoamido sulfone of formula (viii) comprising oxidation of a hydroxysulfonamide of formula (vii) in the presence of an oxidizing agent selected from the group consisting of: a peracid, tert-butyl hydroperoxide, dimethyl dioxirane, selenium dioxide, m-phenanthroline di-N-oxide, nitric acid and hydrogen peroxide. There is also provided a process for preparing an acetoamidosulfone of formula (ix-a) comprising converting a hydroxysulfone of formula (viii) to the acetoamidosulfone of formula (ix-a) in the presence of acetonitrile and an acid. There is also provided a process for separating the cis- and trans-isomers of dorzolamide from a mixture of the trans-isomer of dorzolamide and the cis-isomer of dorzolamide comprising reacting the mixture of isomers with a carboxylic acid.

Dependencies are inferred from the claim text.