GB909751A - 4-chloro-3-sulphamyl benzamides - Google Patents

Abstract

The invention comprises 4-chloro-3-sulphamylbenzamides of the formula: <FORM:0909751/IV (b)/1> wherein R=H or an alkyl group containing up to 3 carbon atoms and R1 = an alkyl group containing up to 3 carbon atoms and a process for the preparation thereof and compounds in addition in which R1 = a phenyl or alkyl substituted phenyl group by reacting 4-chloro-3-nitrobenzoyl chloride with an appropriate amine R R1NH to form a 4-chloro-3-nitrobenzamide of the formula: <FORM:0909751/IV (b)/2> reducing the 4-chloro-3-nitrobenzamide, to obtain the corresponding 4-chloro-3-aminobenzamide, diazotising this compound, treating the resultant diazo compound with a concentrated solution of SO2 in acetic acid containing copper chloride to yield the 4-chloro-3-chlorosulphonylbenzamide of the formula: <FORM:0909751/IV (b)/3> and reacting the sulphonylbenzamide with ammonia. The reductive step may be effected by hydrogenation in the presence of a catalyst or with iron powder in acidulated water or acidulated aqueous ethanol. Diuretic/natriuretic compositions containing the above compounds are employed orally (e.g. in tablets) or for injection in dilute alkaline media or in polyethylene glycol solutions. The Provisional Specification describes also compounds having the above formula wherein R1 = substituted phenyl (e.g. o-, m- and p-chlorophenyl; o-, m- and p-bromophenyl; 2,3-, 2,4-, 2,5-, and 2,6-dichlorophenyl; 2,4,6-trichlorophenyl; o-, m- and p-anisyl, o-carboxyphenyl and o-carboxycarbonylphenyl), and aralkyl groups such as benzyl or phenethyl, and additionally wherein -NRR1 = a heterocylic nucleus such as pyrrolidino, piperidino or morpholino. Reference has been directed by the Comptroller to Specification 882,090.