Novel convenient approach to 1,4,2-benzodithiazine-1,1-dioxides and 1,2,3-benzoxathiazine-2,2-dioxides

Abstract

A new effective method for the construction of 1,4,2-benzodithiazine and 1,2,3-benzoxathiazine scaffolds, based on the use of easily accessible N-chlorosulfonyltrichloroacetimidoyl chloride, has been developed. Reactions of thiophenols involved an initial nucleophilic substitution at the imine carbon atom with a thiol sulfur atom, followed by intramolecular sulfonylation of the benzene ring. Phenols exhibit opposite regioselectivity and react by electrophilic imidoylation of the ortho-carbon atom of the benzene ring (C-C bond formation) and sulfonation of the phenol oxygen atom. Synthesized 1,4,2-benzodithiazine-1,1-dioxides exhibit growth-stimulating activity on monocotyledonous winter wheat "Bezosta" and dicotyledonous plants Barbarea arcuate.

Efficient Synthesis of Fused Heterocycles Incorporating Pyrazole/Thiadiazine or Pyrazole/Thiadiazepine Fragments Using N‐Chlorosulfonyltrihaloacetimidoyl Chlorides

“…mp 181-182 ο C. 1 H-NMR (DMSO-d 6 , 400 MHz) δ 9.50 (br, 1H), 8.46 (br, 1H), 7.82 (s, 1H), 3.77 (s, 3H), 2.41 (s, 3H). 13 Typical procedure for the synthesis of compounds 15 a,b. A solution of 4,7-dihydropyrazolo[4,3-e][1,2,4]thiadiazine-1,1-dioxide 7 a (160 mg 0.5 mmol) or 7 b (300 mg, 0.91 mmol), diethyl phosphite (1 g 7.2 mmol) and DBU (1 g, 6.5 mmol) in 20 mL acetonitrile was stirred at reflux for 5 days.…”

“…In our recent works, we have developed a convenient method for preparing a CÀ N-S-bielectrophilic reagent, Nchlorosulfonyltrichloroacetimidoyl chloride 1 a, and demonstrated its versatility in the synthesis of monocyclic and condensed nitrogen heterocycles bearing 6-, 7-, and 8-membered rings, all of which incorporate an endocyclic sulfonamide fragment. [11][12][13] In this study, we present the synthesis of another novel CÀ N-S-bielectrophilic reagent, BrCF 2 C(Cl) = NSO 2 Cl 1b, and the use of both chlorosulfonyl imidoyl chlorides 1 a and 1 b to construct pyrazolothiadiazine and pyrazolothiadiazepine ring systems, expanding the scope of our synthetic methodology.…”

“…Yield 1.07 g (30 %), cream powder, mp 242-244 °C. 1 H-NMR (DMSO-d 6 , 400 MHz) δ 10.14 (s, 1H, NH), 8.39 (s, 1H), 4.64 (s, 2H), 3.87 (s, 3H) 13. C-NMR (DMSO-d 6 , 125 MHz) δ 150.8 (t, 2 J CF 27 Hz), 141, 132.1, 122.3, 112 (t, CF 309 Hz), 39.5, 39.1.…”

“…Yield 1.19 g (50 %), colorless crystals, mp 257-258 °C (CH 3 CN) 1. H-NMR (DMSO-d 6 , 300 MHz) δ 8.31 (br, NH + H 2 O), 3.68 (s, 3H), 2.27 (s, 3H) 13. C-NMR (DMSO-d 6 , 125 MHz) δ 156.5, 148.5, 139.6, 100.5, 97.2, 33.9, 12.8.…”

“…1 H-NMR (DMSO-d 6 , 400 MHz) δ 3.91 (s, 3H), 2.36 (s, 3H) 13. C-NMR (DMSO-d 6 , 100 MHz) δ 150, 136.3, 123.5, 122.1, 91.7, 38, 11.8.…”