GB570196A - Improvements in and relating to the manufacture of antibacterial sulphanilamido compounds - Google Patents

Abstract

Sulphanilamido compounds having antibacterial properties and of the general formula <FORM:0570196/IV/1> wherein X represents a benzene nucleus which carries a nitrile group in any one of the o-, m-or p-positions to the sulphonamide group, are prepared by interaction of an aminobenzene derivative carrying a nitrile group as a nuclear substituent in the o-, m- or p-position with (a) a benzenesulphonyl halide, advantageously in presence of an acid acceptor, such halide containing in the p-position a substituent readily convertible into an amino group, viz. an amino group protected by an acyl or other easily removable group or a nitro, nitroso, azo, hydrazo or other group capable of reduction to an amino group or a halogen atom, or (b) a benzenesulphonyl ester similarly substituted or substituted by an amino group in the p-position and subsequent conversion of the said convertible substituent, if present, into an amino group, e.g. by mild hydrolysis of an acylamino group, performed so as to leave the nitrile group unaffected. In examples: (1) o-sulphanilamidobenzonitrile is obtained by slowly adding acetylsulphanilyl chloride to o-aminobenzonitrile, in pyridine, heating for 1 hour on the steam-bath, hydrolysing the precipitated N4-acetyl compound by boiling with hydrochloric acid and isolating the free o-sulphonamidobenzonitrile by neutralizing the solution; (2) m-sulphanilamidobenzonitrile; and (3) p-sulphanilamidobenzonitrile are similarly obtained from the m- and p-aminobenzonitriles respectively. o-Aminobenzonitrile is obtained by reduction of the corresponding nitro-compound, which has been specially purified by passing the crude product in benzene through an alumina column, washing the alumina with benzene, concentrating the filtrate and adding light petroleum.