Abstract: A potassium salt useful in the production of certain N-substituted alkyl or arylalkyl thionitroethenamines is produced by the reaction of the dipotassium salt of a 2-nitrodithio aliphatic acid such as 2-nitrodithio acetic acid with branched chain primary alkylamines, secondary alkylamines, arylalkylamines or heterocyclic alkylamines such as dimethylamine, pinacolylamine, benzylamine or piperonylamine, thereby converting one only of the KS-groups to an alkylamine group. The resulting monopotassium salt may be alkylated or arylalkylated to produce an N-substituted alkyl or arylalkyl thionitroethenamine. This compound may be reacted with a suitable amine to produce compounds containing the pharmaceutically active grouping --NHC(.dbd.CHNO.sub.2)NHX, wherein X represents an alkyl, arylalkyl or heterocyclic alkyl group.

Abstract: A potassium salt useful in the production of N-substituted-1-alkylthio-2-nitroethenamines is produced by the reaction of the dipotassium salt of nitrodithioacetic acid with certain straight chain alkylamines, thereby converting only one of the KS-groups to an alkylamine group. The resulting monopotassium salt may be alkylated to produce the required N-substituted-1-alkylthio compound which may be reacted with a suitable amine to produce the histamine H.sub.2 -antagonist ranitidine.