Improvements in or relating to the preparation of beta-thiocarbamyl carboxylic acid compounds

摘要

Beta-thiocarbamyl carboxylic acid salts are made by reacting a saturated aliphatic betalactone with a salt of a thiocarbamic acid. The corresponding acid may be obtained on acidification. Solvents may be present, e.g. alcohols or water, the latter being the most convenient. Preferably equimolar quantities of reactants are used. Highest yields are obtained at 0-100 DEG C., preferably 0-50 DEG C., and at atmospheric pressure. Water-soluble thiocarbamates are preferred. Many thiocarbamates are specified, representative being alkali metal and ammonium salts of methyl, decyl, diketyl, didodecyl, phenyl, dibenzyl, dicyclohexyl, methylene and hexamethylene thiocarbamic acid. Beta-propiolactone is preferred, representative of other lactones specified being betabutyro-, alpha-methyl-beta-propio-, and betamethyl - beta - valero - lactones. In examples: beta-propiolactone is reacted in aqueous solution with (1) ammonium thiocarbamate; and (2) N-butyl ammonium thiocarbamate to give on acidification beta-thiocarbamyl- and (n-butyl - thiocarbamyl) - propionic acid respectively. Specification 649,028 is referred to.