GB773261A - Pyridine-(3)-sulphinic acid, sulphones related thereto, salts thereof and a process for the manufacture of same - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:0773261/IV(b)/1> wherein n is 0, 1 or 2 and R is hydrogen or a substituted phenyl or pyridyl radical when n= 0, or is a phenyl or pyridyl radical or a substitured phenyl or pyridyl radical when n=1 or 2, and salts of these compounds such as the acid addition and quaternary salts, and alkali-metal salts of the sulphinic acid (n=0, R=H), the substituents being halogeno, alkyl, cyano, alkoxy, acyloxy, hydroxy, nitro, acylamino or nitro radicals. The compounds are made by condensing pyridyl-3-sulphonyl chloride with hydrazine, reacting the resulting pyridine-(3)-sulphonic acid hydrazide with a carbonyl compound containing three or more carbon atoms and, if sulphones are required, either condensing the resulting pyridine-(3)-sulphinic acid (in the form of a salt thereof) with a substituted phenyl or pyridyl halide or a nuclear substituted or unsubstituted phenyl - methyl, phenyl - ethyl, pyridyl-methyl or pyridyl-ethyl halide in an organic solvent, or reacting it with the appropriate benzene or pyridine compound containing a double bond adjacent to the phenyl or pyridyl group preferably in a liquid reaction medium such as water or an organic solvent or mixtures thereof, and, if desired, converting any nitro or acylamino substituent present in the product into an amino group by hydrogenation or hydrolysis or any alkoxy or acyloxy group present into a hydroxy group, by hydrolysis, and, if desired, converting the product into a salt. Salts of pyridine-(3)-sulphinic acid are made by neutralizing the acid with the appropriate alkali. Acid addition salts and quaternary salts of the sulphones are made by treatment with the appropriate strong acid or quaternizing agent, suitable quaternizing agents being lower-alkyl halides, alkenyl halides, aryl halides containing an activated halogen such as 1 - chloro - 4 - nitro - benzene, aralkyl halides and phenacyl halides. The amino phenyl sulphones may be produced by reduction of the corresponding nitro-compounds with Raney nickel and hydrogen. Quaternary salts of the amino-phenyl sulphones are made by acetylation of the amino group followed by quaternization and deacylation. Examples describe the preparation by the above methods of pyridine-(3)-sulphinic acid, the corresponding sulphones C4H5N.SO2R1, wherein R1 is 4-nitro-phenyl, pyridyl-(4), nitrobenzyl, p-aminobenzyl, p-acetaminobenzyl, m-nitrobenzyl, p-nitrophenethyl, p-chlorobenzyl, pyridyl-4-methyl, pyridyl-(4)-ethyl and pyridyl-(2)-ethyl and of acid addition and quaternary salts of the sulphones such as the hydrochloride, methyl bromide, propyl bromide, butyl bromide, allyl chloride, benzyl bromide and p-nitrobenzyl bromide.