The Reactions of N,N′-Diphenyldithiomalondiamide with Arylmethylidene Meldrum’s Acids

Abstract

The Michael addition reaction between dithiomalondianilide (N,N′-diphenyldithiomalondiamide) and arylmethylidene Meldrum’s acids, accompanied by subsequent heterocyclization, was investigated along with factors affecting the mixture composition of the obtained products. The plausible mechanism includes the formation of stable Michael adducts which, under the studied conditions, undergo further transformations to yield corresponding N-methylmorpholinium 4-aryl-6-oxo-3-(N-phenylthio-carbamoyl)-1,4,5,6-tetrahydropyridin-2- thiolates and their oxidation derivatives, 4,5-dihydro-3H-[1,2]dithiolo[3,4-b]pyridin-6(7H)-ones. The structure of one such product, N-methylmorpholinium 2,2-dimethyl-5-(1-(2-nitrophenyl)-3-(phenylamino)-2-(N-phenylthiocarbamoyl)-3-thioxopropyl)-4-oxo-4H-1,3-dioxin-6-olate, was confirmed via X-ray crystallography.

6-Amino-4-Aryl-7-Phenyl-3-(Phenylimino)-4,7-Dihydro-3H-[1,2]dithiolo[3,4-B]pyridine-5-Carboxamides: Synthesis, Biological Activity, Quantum Chemical Studies and In Silico Docking Studies

“…In recent papers [30][31][32] we have described the preparation of [1,2]dithiolo [3,4-b]pyridines by reaction of dithiomalondianilide 1 with activated Michael substrates such as substituted acrylonitriles 4,5 (Scheme 4) but no detailed study of the reaction mechanism has been carried. Scheme 4.…”

Alkyl 4-Aryl-6-amino-7- phenyl-3-(phenylimino)-4,7-dihydro- 3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylates: Synthesis and Agrochemical Studies

“…In the context of our interest in exploring the chemistry of dithiomalondianilide 12 and its transformations leading to [1,2]dithiolo[3,4-b]pyridines [ 16 , 19 , 20 , 21 ], it seemed reasonable to study the reactions of dithiomalondianilide 12 with other Michael acceptors. It is noteworthy that despite the long-standing and active use of thioamide 12 as a bidentate S,S-chelating agent towards heavy metals (e.g., [ 22 , 23 , 24 , 25 ]), the heterocyclization reactions of 12 have been little studied to date [ 26 , 27 , 28 , 29 ].…”