A. G. Mal'kina

A mathematical model for the methoxycarbonylation of acetylenic alcohols in the presence of the PdCl2-CuCl2-NaOAc system

Conclusion1.Mathematical planning was used to study the reaction of 3-methyl-l-butyn-3-o1 with carbon monoxide in methanol in the presence of the PdCl2-CuCl2-NaOAc catalytic system, leading to the methyl ester of 4-methyl-4-hydroxy-2-pentynoic acid and equations were obtained describing the effect of the reaction conditions on the yield of this product in the range of variation selected for the major factors.2.The mathematical model was used to show that the yield of the product may be raised by increasing the concentration of CuCl2 and NaOAc with concurrent decrease in the relative amount of the palladium component of this catalyst.

Direct13C-13C spin-spin coupling constants for the triple bond in activated acetylenes

Conclusions13C-13C SSCC values across the triple bond in activated acetylenes are determined primarily by the σ-electronic properties of substituents. The enhanced sensitivity of1Jcc in acetylene derivatives to substituent effects also asserts their possible utility in estimating the electronegative properties of substituents.

Synthesis of substituted 1,3-thiazinoazoles

Substituted 1,3-thiazinoazoles were obtained by treating benzimidazole-2-thione, 4,5-diphenylimidazole-2-thione, and 1,2,4-triazole-3-thione with tertiary cyanoacetylenic alcohols and their acetals in the presence of lithium hydroxide. Treatment of the 1,3-thiazinobenzimidazoles with base destroyed the thiazino ring forming benzimidazol-2-one.

Reactions of imidazolethiones with phenylcyanoacetylene

The reaction of phenylcyanoacetylene with imidazolethiones was studied. It is shown that in the presence of 5–10% KOH the addition of phenylcyanoacetylene is accompanied by intramolecular cyclization with the formation of imidazo-1,3-thiazines. An increase in the amount of catalyst to 20% leads to cleavage of the thiazine ring at the C-S bond and the formation of the corresponding acrylonitrile derivatives. Products of addition of 2 moles of phenylcyanoacetylene were obtained.

Synthesis of 1,2,4-triazolo[3,2-b]-1,3-thiazines

Abstract1,2,4-Triazolo[3,2-b]-1,3-thiazines were obtained by the reaction of 1,2,4,-triazole-3-thiones with an equimolar amount of 1-phenyl-2-cyanoacetylene in the presence of triethylamine or potassium hydroxide. It is shown that triazolethiones form N,S diadducts upon reaction with a twofold excess of cyanoacetylene. The nature of the heteroatom in the exo position of the heteroring affects the direction of addition to phenylcyanoacetylene. 2,4-Bis(1-phenyl-2-cyanovinylene)-1,2,4-triazol-3-one was synthesized.

CYANOACETYLENE AND ITS DERIVATIVES. 3. BASE‐CATALYZED AUTOHETEROCYCLIZATION OF CYANOACETYLENE CARBINOLS

Behandelt man 1-Cyan-3,3-dialkyl-3-hydroxy-1-propin (II) mit NaOH-haltigem Dioxan, so entsteht 2,2-Dia1ky1-3,4-di-cyanmethyliden-oxethan (IV).

Cyanoacetylene and its derivatives

ConclusionsTertiary cyanoacetylenic carbinols in the presence of alkalis undergo autoheterocyclization with the formation of 2,2-dialkyl-4,5-di(cyanomethylidene)oxetanes.

Cyanoacetylene and its derivatives 2. Reaction of isomeric cyanomethylacetylene-cyanoallene with glycols

ConclusionsThe reaction of isomeric cyanomethylacetylene-cyanoallene with glycols gives cyclic acetals and glycol mono- and diethers as a result of nucleophilic attack on the central atom of the allene system.