Abstract: The present invention discloses a process for the synthesis of fosinopril as a single desired isomer of high purity in two steps comprising of (a) preparation of fosinopril as a mixture of four diastereomers and (b) separation of the desired isomer from the mixture through formation of alkali metal salts followed by crystallisation.

Abstract: The present invention discloses a process for the synthesis of fosinopril as a single desired isomer of high purity in two steps comprising of (a) preparation of fosinopril as a mixture of four diastereomers and (b) separation of the desired isomer from the mixture through formation of alkali metal salts followed by crystallisation.

Abstract: An improved regiospecific synthesis of organic phosphonous acids, comprising of hydrophosphorylation of an olefin with hydrophosphorous acid in the presence of an inorganic persulfate, which acts as a source of free radicals at a pH ranging from 4.5 to 7.0, in which the orientation of addition is anti-Markonikoff. The process enables production of organic phosphonous acids at lower temperature and atmospheric pressure under milder pH conditions for better regioselectivity in hydrophosphorylation and obtain the phosphonous acid with good yield and purity following simple isolation procedure. Phosphonous acids obtained by the process are commercially valuable as effective detergents and wetting agents, lubricants and lubricant additives, plasticizers for plastics and resins, corrosion inhibitors, chemicals including insecticides and pesticides, cobalt extractants and as key intermediates for preparation of commercially important angiotensin converting enzyme (ACE) inhibitors.