Regioselective synthesis of heterocyclic N-sulfonyl amidines from heteroaromatic thioamides and sulfonyl azides

• Vladimir Ilkin,
• Vera Berseneva,
• Tetyana Beryozkina,
• Tatiana Glukhareva,
• Lidia Dianova,
• Wim Dehaen,
• Eugenia Seliverstova and
• Vasiliy Bakulev

Beilstein J. Org. Chem. 2020, 16, 2937–2947, doi:10.3762/bjoc.16.243

• synthesis of various types of sulfur containing heterocyclic compounds [43][44][45][46][47]. This gives some promise to the development of a general and efficient method for the synthesis of N-sulfonyl amidines of heteroaromatic acids based on the reaction of heterocyclic thioamides with higly electrophilic

• form can be explained by steric hindrance between the phenyl and the arylsulfonyl groups. Because of the observed evolution of nitrogen and sulfur in every reaction of heterocyclic thioamides and sulfonyl azides it is logic to propose the formation of a thiatriazole ring via [3 + 2] cycloaddition of

• -triazole-4-carbothioamides 1i–l with azides 2a,c–f. Synthesis of 2-aminothiazole-4-N-sulfonyl amidines. Synthesis of N-sulfonyl amidines of isoxazolylcarboxylic acid. Synthesis of bis(sulfonyl amidines) 3aj–an. Plausible mechanism for the reaction of heterocyclic thioamides with sulfonyl azides

A novel method for heterocyclic amide–thioamide transformations

• Walid Fathalla,
• Ibrahim A. I. Ali and
• Pavel Pazdera

Beilstein J. Org. Chem. 2017, 13, 174–181, doi:10.3762/bjoc.13.20

• ; heterocyclic thioamides; N-cyclohexyl dithiocarbamate cyclohexylammonium salt; novel thiating agent; thiation; Introduction Transforming heterocyclic amides into thioamides is an important task in organic synthesis. Earlier reports for this type of O/S conversions were achieved by several thiating reagents

• efficient method for the transformation of heterocyclic amides to heterocyclic thioamides gained great attention. The reaction of three molar equivalents of cyclohexylamine (1) with one molar equivalent of carbon disulfide in water typically afforded N-cyclohexyl dithiocarbamate cyclohexylammonium salt (2

• dicyclohexylthiourea (3, Scheme 2). We have extended the scope of this process to involve the transformation of a number of heterocyclic amides; quinazolin-4(3H)-one (A1), 2-substituted quinazolin-4(3H)-one A3–A6 and 4-subsituted phthalazin-1(2H)-ones A7 and A8 into the corresponding heterocyclic thioamides C1 and C3