Synthesis, structure and reactivity of 4-phosphanylated 1,3-dialkyl-imidazole-2-thiones

Selective formation of 4-phosphanylated 1,2-dialkyl imidazole-2-thiones 3a-f has been obtained via a lithiation followed by phosphanylation reaction. The reactivity of 3a-f was examined towards oxidation and complexation reactions. All products were unambiguously characterized by elemental analyses, spectroscopic and spectrometric methods including X-ray analysis (3a, 3b, 4b, 4d, 5b, 6a and 6d).     

4-Dimethylaminoacetophenone O-vinyloxime: Synthesis and steric structure

4-Dimethylaminoacetophenone oxime was synthesized from 4-dimethylaminoacetophenone and hydroxylamine hydrochloride. Its reaction with acetylene in the system KOH-DMSO gave previously unknown 4-dimethylaminoacetophenone O-vinyloxime as the major product. According to the experimental data and quantum-chemical calculations, 4-dimethylaminoacetophenone O-vinyloxime is formed as the only E isomer with preferential s-trans conformation of the vinyloxy group, which is characterized by essentially nonplanar structure.     

Synthesis of imidazoline-2-thiones and imidazolidine-2-thiones

1-Aryl (or alkyl)-4,5-( -glucopyrano)imidazolidine-2-thiones are obtained by condensation of 2-amino-2-deoxy- -glucose with aryl (or alkyl) isothiocyanates. 1-Aryl-4- -arabinotetrahydroxybutylimidazoline-2-thiones are prepared by reaction of N-arylamino-1-deoxy- -fructoses with potassium thiocyanate. A comparative structure study of both types of compound is reported.     

Synthesis of isomeric 4- and 5-hydroxylaminothiazolidin-2-thiones

Tsomeric 4- and 5-hydroxylaminothiazolidin-2-thiones were synthesized by the reaction of 1,2-aminosubstituted oximes with CS₂, and of dimeric olefin nitrosochlorides with dithiocarbamate salts. These compounds react with aldehydes and ketones to form the respective nitrones. In contrast to the 5-derivatives, the 4-hydroxylamino derivatives hydrolyze to 4-hydorxythiazolidin-2-thiones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 549–553, April, 1986.     

Reactivity and stereochemical structure of 4-hydroxy- and 4-alkoxyhexahydropyrimidine-2-thiones

Substituted 4-hydroxyhexahydropyrimidine-2-thiones were obtained by the reaction of -isothiocyanatoaldehydes with ammonia or methylamine. When heated with alcohols in the presence of p-toluenesulfonic acids, the synthesized compounds gave the corresponding 4-alkoxyhexahydropyrimidine-2-thiones, which were converted into other 4-alkoxy derivatives by the action of the respective alcohols and were hydrolyzed to the initial 4-hydroxyhexahydropyrimidine-2-thiones by the action of an aqueous solution of oxalic acid or potassium hydroxide. The reaction of the 4-hydroxyhexahydropyrimidine-2-thiones with methyl iodide led to the formation of 2-methylthio-4-hydroxy-3,4,5,6-tetrahydropyrimidine hydriodides. It was shown by PMR spectroscopy that the stereoisomers in which the hydroxyl (or alkoxyl) group has the axial orientation are thermodynamically more stable.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 260–266, February, 1985.     

Synthesis and ring-chain tautomerism of substituted 4-hydroxy-hexahydropyrimidine-2-thiones

The synthesis of a number of substituted 4-hydroxyhexahydropyrimidine-2-thiones has been effected. The prototropic ring-chain tautomerism of compounds of this type in chloroform solution has been investigated by IR spectroscopy. The dependence of the relative stability of the cyclic tautomeric forms on the structures of the compounds studied has been elucidated.     

Reduction of 4-hydroxy(alkoxy)hexahydropyrimidine-2-thiones and 1,2,3,6-tetrahydropyrimidine-2-thiones by the NaBH4-CF3COOH system. Synthesis of hexahydropyrimidine-2-thiones

A convenient method for the synthesis of hexahydropyrimidine-2-thiones by the reduction of the readily accessible 4-hydroxy(alkoxy)hexahydropyrimidine-2-thiones and 1,2,3,6-tetrahydropyrimidine-2-thiones by the NaBH₄-CF₃COOH system was proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1378–1388, October, 1993.     

Synthesis of 5-substituted 4-methylthio-1,3-thiazoline-2-thiones

Translated from Khimiya Geterotsiklicheskih Soedinenii, No. 2, pp. 276–277, February, 1989.     

Synthesis of 1-Benzoyl-3-aryl-4-hydroxy-4-phenylimidazolidin-2-thiones

l-Benzoyl-3-aryl-4-hydroxy-4-phenylimidazolidin-2-thiones can be synthesized readily from the cyclization of 1-benzoyl-3-arylthioureas with bromine-acetophenone in the presence of excess triethylamiqe.     

Synthesis and use of 4-azidohexahydropyrimidin-2-thiones as efficient amidoalkylating reagents

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 133–134, January, 1990.     

A Procedure for Synthesis of 3-Halomethyl-4-oxothiazolidine-2-thiones

Solid-phase synthesis of 3-halomethyl-4-oxothiazolidine-2-thiones was perforomed.     

Synthesis and steric structure of 1,3(1,5)-dimethyl-2-phenyl-and -2,4-diphenyl-4-piperidols

1,3(1,5)-dimethyl-2-phenyl- and -2,4-diphenyl-4 piperidols were respectively obtained with the reaction of 1,3-and 1,5-dimethyl-2 phenyl-4-piperidoraes with sodium borohydride and phenyllithium. The steric isomers of the compounds obtained were separated and identified by spectral methods.Moscow State Academy of Precision Chemical Technology, Moscow 117571. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 941–945, July, 1994. Original submitted July 11, 1994.     

Synthesis of N-Substituted Benzimidazole-2-thiones

General methods were developed for N-substitution of benzimidazoline-2-thione with alkyl, alkenyl, alkynyl and acyl groups using S-tritylation as a protecting reaction.     

Efficient Synthesis of 3-Acyl-5-arylmethylene-4-oxothiazolidine-2-thiones

An efficient procedure was suggested for preparing 3-acyl-5-arylmethylene-4-oxothiazolidine-2-thiones.     

Synthesis,structure, and reactivity of l,2,3,6-tetrahydropyrimidine-2-thiones

Dehydration of 4-hydroxyhexahydropyrimidine-2-thiones formed 1,2,3,6-tetrahydropyrimidine-2-thiones containing no substituent at the C₍₄₎ carbon atom. It is shown that the synthesized compounds, in contrast to their 4-alkyl-substituted analogs, react easily with various nucleophilic reactants (alcohols, butylmercaptan, benzenesulfinic acid, hydrazoic acid, p-toluidine) to form the corresponding 4-functionally substituted hexahydropyrimidine-2-thiones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1259–1270, September, 1993.     

Nucleophilic substitution at the C(4) atom in series of functionally 4-substituted hexahydropyrimidine-2-thiones. Synthesis of 4-alkylthiohexahydropyrimidine-2-thiones

Nucleophilic substitution at the C₍₄₎ atom in 4-hydroxy(alkoxy)hexahydropyrimidine-2-thiones under the influence of alkanethiols in acidic, neutral, and basic media, as a result of which 4-alkylthiohexahydropyrimidine-2-thiones are formed, was studied. Hydrolysis and alcoholysis of the latter lead to the corresponding 4-hydroxy- or 4-alkoxyhexahydropyrimidine-2-thiones. The three-dimensional structures of the 4-alkylthiopyrimidines obtained were established by PMR spectroscopy, and it was shown that the stereoisomers with an axially oriented alkylthio group are thermodynamically more stable.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 234–240, February, 1988.     

Synthesis of polyacrylamide samples of known steric structure

The esterification of atactic, syndiotactic and isotactic samples of poly(acrylic acid) by phenol and p-nitrophenol, carried out at 95° in the presence of POCl₃, led only to atactic poly(phenyl and p-nitrophenyl acrylates) respectively, as shown by ¹H-NMR (250 MHz). These polymers and isotactic poly(phenyl acrylate), prepared by anionic polymerization of phenyl acrylate with n-butyllithium, when reacted with ammonia led to bridged polyacrylimides or to linear atactic or isotactic polyacrylamides according to the reaction conditions. Anionic homopolymerization of p-nitrophenyl acrylate did not occur.