Sulphur nitrides in organic chemistry. Part 5. The reaction of tetrasulphur tetranitride with oximes and imines

Abstract

The reaction of tetrasulphur tetranitride (N₄S₄)(1) with oximes (2a–d) and imines (3a and b) was carried out under refluxing condition in toluene. It was found that the N–O bond in benzophenone oxime (2a) or fluorenone oxime (2b) was cleaved by (1) to afford the corresponding imino-sulphides such as bis(diphenylmethyleneamino) sulphides (4) or bis(fluorenylideneamino) sulphides (7) together with benzophenone (5) and benzanilide (6), or fluorenone imine (3a), fluorenone (8), and fluorenylideneaminosulphenamide (9), respectively. The reaction of (1) with (3a) was carried out under the same conditions to give the expected bis(fluorenylideneamino) monosulphide (7a) together with the trisulphide (7b), (8), and (9). Similarly phenanthrenequinone monoimide (3b) afforded the bis(oxophenanthrenylideneamino) monosulphide (13) in 83% yield. From these results, it can be concluded that imines are probably an intermediate in the formation of the imino-sulphides (4) and (7). In contrast to (2a and b), cyclohexanone oxime (2c) afforded only large amounts of tarry materials. It was also found for the reaction with benzil monoxime (2d) that not only the N–O bond but also the C–C bond of (2d) was cleaved with (1) to afford benzamide (10) and benzonitrile (11) together with 3,4-diphenyl-1,2,5-thiadiazole (12).