10.1039/jr9530004089
The study investigates the reaction of hydrogen sulphide and formaldehyde with aromatic amines such as aniline and p-toluidine. The researchers found that these amines can condense with hydrogen sulphide and formaldehyde to form various compounds, including tetrahydrothiadiazines, thia-azetidines, and dihydrodithiazines. The specific products formed depend on the proportions of the reactants used. For instance, when 1 mol of hydrogen sulphide in aqueous-ethanolic formaldehyde is condensed with 2 mols of the amine, tetrahydrothiadiazines are obtained. However, when 2 mols of hydrogen sulphide are condensed with 1 mol of amine, mixtures of thia-azetidines and dihydrodithiazines are produced. The study also notes that all the cyclic products rapidly decompose to trithioformaldehyde and the amine hydrochloride when heated with hydrochloric acid.