3,3'-Thio-di-propionamide prodn. - by reacting acrylamide with hydrogen sulphide in presence of aqueous base

In a new process for prodn. of beta, beta'-thiodipropionamide (I), acylamide is reacted in aqueous medium of 20-80 degrees C with H2S in the presence of 0.01-0.01 equivalents of a water-soluble base, the pH in the reaction soln. not exceeding 8. (I) is used as an antioxidant for polyethylene (US 2981717). It is also useful as an intermediate for stabilisers, softening agents, and synergists for insecticides herbicides and plant growth regulants. Carrying out the reaction in the presence of a water-soluble base gives high yields and (I) is obtd. highly pure form. In an example, H2S is passed into 0.06-M NaOH (250 ml) until pH 7.5 is reached, then acrylamide (71g) is added and H2S (10% excess) is passed into the mixture for 4 hrs. at 40 degrees C. After cooling in ice (I) is filtered off. Yield 85g (=96.5%).