Synthesis of 4-oxothiazolidine-2,5-diylidenes containing thioamide group based on dithiomalonamides

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

New [1,2]dithiolo[3,4-b]pyridine-5-carboxamides were synthesized through the reaction of dithiomalondianilide (N,N'-diphenyldithiomalondiamide) with 3-aryl-2-cyanoacrylamides or via a three-component reaction involving aromatic aldehydes, cyanoacetamide and dithiomalondianilide in the presence of morpholine. The structure of 6-amino-4-(2,4-dichloro- phenyl)-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxamide was confirmed using X-ray crystallography. To understand the reaction mechanism in detail, density functional theory (DFT) calculations were performed with a Grimme B97-3c composite computational scheme. The results revealed that the rate-limiting step is a cyclization process leading to the closure of the 1,4-dihydropyridine ring, with an activation barrier of 28.8 kcal/mol. Some of the dithiolo[3,4-b]pyridines exhibited moderate herbicide safening effects against 2,4-D. Additionally, ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) parameters were calculated and molecular docking studies were performed to identify potential protein targets.

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

The reaction between dithiomalondianilide (N,N'-diphenyldithiomalondiamide) and alkyl 3-aryl-2-cyanoacrylates in the presence of morpholine in the air atmosphere leads to the formation of alkyl 6-amino-4-aryl-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]- pyridine-5-carboxylates in 37-72% yields. The same compounds were prepared in 23-65% yields by ternary condensation of aromatic aldehydes, ethyl(methyl) cyanoacetate and dithiomalondianilide. The reaction mechanism is discussed. The structure of ethyl 6-amino-4-(4-methoxyphenyl)-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylate was confirmed by X-ray crystallography. Two of the prepared compounds showed a moderate growth-stimulating effect on sunflower seedlings. Three of the new compounds were recognized as strong herbicide safeners with respect to herbicide 2,4-D in the laboratory and field experiments on sunflower.

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

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.

N,N'-Diphenyldithiomalonodiamide: Structural Features, Acidic Properties, and In Silico Estimation of Biological Activity

The spectral characteristics of dithiomalondianilide (N,N'-diphenyldithiomalonodiamide) were studied, and the dissociation constant was determined by potentiometric titration. Quantum-chemical methods at the B3LYP-D3BJ/6-311+G (2d,p) level were used to calculate the molecular geometry and vibrational spectra of the most stable tautomeric forms of dithiomalondianilide. The bioavailability parameters were calculated, and possible protein targets were predicted by the protein ligand docking method.

Skeletal rearrangement of arylmethylideneimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7-diones in the synthesis of the corresponding imidazo[4,5-e]thiazolo[2,3-c]-1,2,4-triazine-2,8-diones

The synthesis of benzylideneimidazo[4,5-e]thiazolo[2,3-c]- 1,2,4-triazines via an alkali-induced skeletal rearrangement of imidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazines is reported.

Crystal structure of (2Z)-2-{(5Z)-5-[3-fluoro-2-(4-phenylpiperidin-1-yl)benzylidene]-4-oxo-3-(p-tolyl)-1,3-thiazolidin-2-ylidene}-N-(p-tolyl)ethanethioamide dimethyl sulfoxide monosolvate

The title compound, C₃₇H₃₄FN₃OS₂·C₂H₆OS, was obtained by the Knoevenagel condensation. The thia­zolidine ring is essentially planar (r.m.s. deviation = 0.025 Å) and forms dihedral angles of 4.2 (3), 68.60 (14) and 39.57 (15)° with the attached thio­amide group, p-tolyl group benzene ring and fluoro-substituted benzene ring, respectively. The exocyclic double bonds are in a Z configuration. In the crystal, the dimethyl sulfoxide solvent mol­ecule is connected to the main mol­ecule via an N—H⋯O hydrogen bond. Weak C—H⋯O hydrogen bonds link the components of the structure into a two-dimensional network parallel to (10-1). Weak intra­molecular C—H⋯S hydrogen bonds are also observed. The crystal is an inversion twin with a ratio of twin components 0.78 (2):0.22 (6).