V. R. Akhmetova

Multicomponent reactions of amines with aldehydes and H2S as efficient route to heterocycles and thioaza macrocycles

Here we provide new experimental results on multicomponent reactions of amines with aldehydes and H2S in the directed synthesis of functionally-substituted 1,3-thiazetidines, 1,3,5-dithiazinanes, 1,3,5-thiadiazinanes, 1,5-dithia-3,7-diazacyclooctanes, and thioaza macrocycles. X-ray analysis gave insight into the structure of the synthesized compounds. New kinds of multicomponent reactions (MCR) have been discovered and characterized.

Multicomponent condensation of aliphatic amines with formaldehyde and hydrogen sulfide

Cyclothiomethylation of primary aliphatic amines with the reagent H2S-CH2O (2:3) in aqueous medium mainly gave substituted dithiazines; oxathiazines and dioxazines were obtained from butylamine and ethanolamine. Under the chosen reaction conditions, ethylenediamine was converted into 5-[2-(perhydro-1,3,5-dithiazin-5-yl)ethyl]perhydro-1,3,5-dithiazine or substituted thiazetidine and oxazetidine, depending on the order of mixing of the starting reagents.

Novel 1,5,3-dithiazepanes: three-component synthesis, stereochemistry, and fungicidal activity

Three-component heterocyclization of hydrazine with formaldehyde and ethane-1,2-dithiol gave previously unknown 3,3′-bi(1,5,3-dithiazepane). Its stereochemistry was determined by X-ray diffraction. The reaction with higher aliphatic aldehydes RCHO (R = Me, Et, Prn, and Bun) yielded 2,4-dialkyl-3-alkylideneamino-1,5,3-dithiazepanes. The stereochemistry of the latter was determined by 1H and 13C NMR spectroscopy and confirmed by quantum chemical calculations. Heterocyclizations of phenylhydrazine and benzylhydrazine with ethane-1,2-dithiol gave 3-amino-1,5,3-dithiazepanes only with CH2O and MeCHO as the aldehyde component. 3,3′-Bi(1,5,3-dithiazepane) and its N-adduct with MeI were found to exhibit fungicidal activity against microscopic fungi.

Thiomethylation of amino alcohols using formaldehyde and hydrogen sulfide

Three-component condensations of formaldehyde with hydrogen sulfide and hydroxylamine or amino alcohols at a ratio of 3:2:1 give 47–73% of N-hydroxy(or hydroxyalkyl)-1,3,5-dithiazinanes. The reactions of CH2O with H2S and hydroxylamine or α-amino alcohols at a ratio of 4:3:1 involve both amino and hydroxy groups, leading to the corresponding dithiazinanes. 4-Aminobutan-1-ol reacts with CH2O and H2S under analogous conditions only at the amino group to form 4-(1,3,5-dithiazinan-5-yl)butan-1-ol.

Multicomponent heterocyclization of carboxamides with H2S and CH2O

Multicomponent heterocyclization of aliphatic amides with H2S and CH2O (1:3:2) in water-organic solvent mixture in the presence of BuONa led to the formation of 1,3,5-dithiazinane in high yield (30–95%) and with high selectivity (100%). Under these conditions benzamide gave 3,5-dibenzoyl-1,3,5-thiadiazinane in 74% yield, whereas due to ortho-effect the acetylsalicylamide with H2S and CH2O in a system BuOH-H2O without BuONa formed N-acetylsalicyloyl-1,3,5-dithiazinane (80%). Heterocyclization of α-aminosuccinic acid monoamide depending on the H2S and CH2O concentration occurred either at one or both NH2 yielding respectively mono-or bisdithiazinanes.

Multicomponent heterocyclization of hydrazine, hydrogen sulfide, and formaldehyde

Multicomponent heterocyclization of hydrazine, hydrogen sulfide, and formaldehyde gave previously unknown bi-, tri-, and tetracyclic nitrogen- and sulfur-containing heterocycles. 3,7-Dithia-1,5-diazabicyclo[3.3.0]octane, 4,9-dithia-1,2,6,7-tetraazatricyclo[5.3.1.12,6]dodecane, and 4,9,14-trithia-1,2,6,7,11,12-hexaazatetracyclo[10.3.1.12,6.17,11]octadecane were obtained selectively, depending on the reaction temperature (0–60 °C).

One-pot cyclothiomethylation of amines as efficient method for the synthesis of saturated five-, six-, seven-, and eight-membered S,N-Heterocycles

The review generalizes and systemizes published data on the synthesis of biologically active saturated five-, six-, seven-, and eight-membered S,N-heterocycles. Particular attention is given to cyclothiomethylation of various amines by the action of two-component systems CH2O-H2S (or thiols) and RCHO-CS2 (or S2Cl2).

Heterocyclization of dimethyl malonate with SH acids and formaldehyde in the presence of catalysts

Three-component heterocyclization of dimethyl malonate with SH acids (H2S, ethane-1,2-dithiol) and formaldehyde in the presence of 5 mol % of transition metal chlorides (FeCl3, CoCl2, NiCl2) gave dimethyl 1,3-dithiane-5,5-dicarboxylate and dimethyl 1,4-dithiepane-6,6-dicarboxylate. The reactions in the presence of transition metal chlorides hydrates were accompanied by Krapcho decarboxylation with formation of methyl 1,3-dithiane-5-carboxylate and methyl 1,4-dithiepane-6-carboxylate.

Thiomethylation of aromatic amines: efficient method for the synthesis of heterocyclic compounds

Primary aromatic amines were thiomethylated by formaldehyde and hydrogen sulfide. N-Substituted 1,3-thiazetidines, 4,5-dihydro-1,3,5-dithiazines, 3,4,5,6-tetrahydro-2H-1,3,5-thiadiazines, and 4,5-dihydro-1,3,5-oxathiazines were prepared for the first time starting from meta- and para-toluidines, meta-, para-, and ortho-anisidines, and para-xylidine. Amines characterized by higher mobility of hydrogen atoms produced previously unknown four-membered thiazetidines, whereas amines characterized by lower mobility of hydrogen atoms gave six-membered thiadiazines. The sorption properties with respect to silver were studied for the compounds, which were prepared from p-toluidine and p-anisidine.

One-pot synthesis of bis-1,5,3-dithiazepanes from ethane-1,2-dithiol, formaldehyde, and ammonium salts

An efficient one-pot procedure has been developed for the synthesis of bis-1,5,3-dithiazepanes by reaction of ethane-1,2-dithiol with formaldehyde and ammonium salts. According to the X-ray diffraction data, the heterorings in 3,3′-[ethane-1,2-diylbis(sulfanediylmethanediyl)]bis(1,5,3-dithiazepane) in crystal adopt a chair conformation with axial orientation of the substituent on the nitrogen atom.