Formation of Sommelet-Hauser-Type Products, 2-Aminoarylmethyl Sulphides, and Nitrenium Ion Products, 2- and 4-Aminoaryl Sulphides, via an N-Arylazasulphonium Salt
Reactions of a salt (1) formed at -60 deg C from trifluoroacetic anhydride and dimethyl sulphoxide (DMSO) with primary and secondary arylamines gave 2-aminoarylmethyl sulphides (6), (6') and (12) by a Sommelet-Hauser rearrangement of an ylide (5) formed by loss of a methyl proton of an N-arylazasulphonium salt (3) in the absence of base.The use of ethyl methyl sulphoxide instead of DMSO afforded a similar product (19b) by loss of not the ethyl but the methyl proton.However, the use of diethyl sulphoxide merely caused loss of an ethyl group from the N-arylazasulphonium salt to yield ethanesulphenanilide (20).The reaction of (1) with N-phenyl-1-naphthylamine gave mainly aminoaryl sulphides (13) and (14) via an arylnitrenium ion from the N-arylazasulphonium salt.In fact, the reaction of dimethyl sulphide (DMS) with arylnitrenium ions formed in the acid decomposition of aryl azides gave no Sommelet-Hauser-type products but 2- and 4-aminoaryl sulphides (22), (22') and (23).We also discuss the possibility of the N-arylazasulphonium salt being formed by reaction of the arylnitrenium ion with DMS.