GB563629A - Sulphanilamido pyridazine - Google Patents

Abstract

Para - substituted benzene sulphonamido pyridazines of the formula <FORM:0563629/IV/1> where Y is a nitro or acylamino radical, X is hydrogen, an alkyl radical or an alkali metal, and Pa is a pyridazine or an alkyl or phenyl substituted pyridazine, are prepared by reacting an amino pyridazine with a p-Y-benzenesulphonyl halide, and if desired forming the free p-amino compound by hydrolysis or reduction. The condensation is preferably carried out in the presence of a base, such as sodium hydroxide, or in the presence of a basic solvent, such as triethylamine or pyridine. If desired, the sodium formaldehyde sulphoxylate amino compound and the mono aldose amino compound may be prepared by reaction with an alkali metal sulphoxylate or a mono-aldose sugar, such as glycose or galactose. In examples: (1) 3-Aminopyridazine is reacted with acetylsulphanilyl chloride in pyridine solution to form 3 - acetylsulphanilamido - pyridazine. (2) The product of example 1 is hydrolysed with aqueous sodium hydroxide to the free p-amino compound. (3) 3-Aminopyridazine is reacted with p-nitrobenzenesulphonyl chloride in pyridine solution to give 3-p-nitrobenzenesulphonamidopyridazine which is reduced in example (4) to the free amino compound by iron dust and acetic acid, and treated with sodium formaldehyde sulphoxylate in example (5) to form the sodium formaldehyde sulphoxylate derivative. (6) As in example 1 but using 3-amino-6-methyl pyridazine instead of the unsubstituted pyridazine to obtain the corresponding product which is hydrolysed in example (7) with aqueous sodium hydroxide. (8) As in example 1, using 3 - amino - 6 - phenylpyridazine, to obtain the corresponding product which is hydrolysed in example (9) with aqueous sodium hydroxide. (10) As in example 1 but using 3-amino-4 : 5 : 6-trimethyl pyridazine to obtain the corresponding substituted pyridazine product which is hydrolysed in example (11) with sodium hydroxide to form the free amino compound.