L. S. Konstantinova

Chapter 4 Sulfur Monochloride in the Synthesis of Heterocyclic Compounds

Publisher Summary The reactions described in this chapter explain that sulfur monochloride is an important reagent for the synthesis of heterocycles with various numbers of sulfur atoms and even without sulfur. An important feature of this reagent is that it can add not only two sulfur atoms to the molecule, as might be expected, but also one, three, four, five, or even more atoms and the structure of the final compound often depends on its stability. The recent developments in the use of sulfur monochloride include: the discovery of its ability to form complexes with organic bases and of the significant difference in reactivity of these complexes from S2Cl2. A selective synthesis of particular heterocycles require accurate conditions like temperature, solvent, catalyst, and base.

Synthesis of nitro, nitroso, azo, and azido derivatives of (4-R1-5-R2-1,2,3-triazol-1-yl)-1,2,5-oxadiazoles by oxidation and diazotization of the corresponding amines

Nitro-, nitroso-, and azo-1,2,5-oxadiazoles with 4-R1-5-R2-1,2,3-triazol-1-yl substituents were synthesized by oxidation of amino-(1,2,3-triazol-1-yl)-1,2,5-oxadiazoles (aminotriazolylfurazans). Azido-1,2,5-oxadiazole was prepared by diazotization of amino(triazolyl)furazan followed by treatment of the diazonium salt with sodium azide. Depending on the nature of the substituents and the reagent, triazolylfurazans can undergo destruction to give amino-R-furazans (R = NO2, N3, aminofurazanylazo), the amino group being formed from the triazole ring.

Oxidative macrocyclocondensation of 3,4-diaminofurazan and 4,4′-diamino-3,3′-azofurazan with dibromoisocyanurate. Crystal structures of hexa- and octadiazenofurazan macrocycles

The oxidative cyclocondensation of 3,4-diaminofurazan and 4,4′-diamino-3,3′-azofurazan with dibromoisocyanurate afforded macrocyclec polydiazenofurazans. The reaction can be directed towards the formation of both the four-membered cycle alone or the three-, six-, and eight-membered macrocycles.

Novel method for synthesis of 3,4:7,8:11,12:15,16-tetrafurazano-1,2,5,6,9,10,13,14-octaazacyclohexadeka-1,3,5,7,9,11,13,15-octaene and its crystal structure

We have established the formation of a tetradiazenofurazan macrocycle as a result of intramolecular oxidative cyclization of 4,4′-bis(4-aminofurazanyl-3-azo)-3,3′-azofurazan and have studied its crystal structure.

Regioselective synthesis of pentathiepines fused with pyrrole, thiophene, or indole rings

Pentathiepines fused with pyrrole, thiophene, or indole rings were obtained by reactions of the corresponding heterocycles or their tetrahydro derivatives with a prepared mixture of sulfur monochloride and DABCO.

Transformations of N-ethylamines into amide derivatives under the action of sulfur monochloride

Tertiary N-ethylamines were converted into amide derivatives by reactions with sulfur monochloride and DABCO at 0 °C. Depending on the nature of the substituents in the amine, the reaction can be accompanied by unexpected transformations.

Synthesis of 4-R-3-(4-R1-5-R2-1,2,3-triazol-1-YL)furazans. 1. Azidofurazans in 1,3-dipolar cycloaddition reactions with substituted acetylenes

The 1,3-dipolar cycloaddition of azidofurazans to substituted acetylenes has been studied and substituted 3-(1,2,3-triazol-l-yl)furazans have been synthesized.

Synthesis of 1,2,5,6-tetrathiocines from fused 1,2,3,4,5-pentathiepines

Abstract1,2,3,4,5-Pentathiepines fused with the pyrrole, thiophene, and indole systems react with sodium cyanide in acetonitrile to form the corresponding tri-and pentacyclic fused 1,2,5,6-tetrathiocines. In the case of unsymmetric pentathiepines annulated at the b side of thiophene or indole, mixtures of isomeric tetrathiocines (∼1: 1) are formed.

Nitro derivatives of 2,1,3-benzothiadiazole 1-oxides: synthesis, structural study, and NO release

A convenient one-pot synthesis of nitro derivatives of 2,1,3-benzothiadiazole 1-oxides by the reaction of o-nitroanilines with sulfur monochloride was developed. The structural features of 4-nitrobenzothiadiazole and its N-oxide were considered. High in vitro release of nitric oxide (69%) was found for a 6-nitro-2,1,3-benzothiadiazole sample by the Griess assay, which indicated good prospects for this class of compounds.

Synthesis of 4-substituted 3-chloro-1,2,5-thiadiazoles from monosubstituted glyoximes

One-pot synthesis of 3-chloro-1,2,5-thiadiazoles from monosubstituted glyoximes and sulfur monochloride was developed.