Seven-membered heterocycles. VIII. 1-Benzothiepin sulfoxides and a convenient synthesis of sulfoxides

Abstract

The following sulfoxides were prepared by the oxidation of the corresponding sulfides with a nitric acid-acetic anhydride mixture: 5-hydroxy-2,3,4,5-tetrahydro-l-benzothiepm 1-oxide (2, 64% yield), 5-chloro-2,3,4,5-tetrahydro-l-benzothiepin 1-oxide (5, 43% yield), and 3,4-dihydro-l-benzothiepin-5(2fl>one 1-oxide (8, 45% yield).2,3-Dihydro-l-benzothiepin 1-oxide (II) was available by oxidation of the sulfide 10 with sodium metaperiodate or sulfuryl chloride ( -78°) followed by hydrolysis. The latter method has been shown to be a general procedure for the synthesis of sulfoxides in high yields. The intermediate in this synthesis appears to be a chlorine sulfide complex which at low temperature is best represented by the tetracovalent sulfur structure 14b.

Oxidation and chlorination reactions of perfluoroketene-N,S-acetals

“…Oxidative property of sulfuryl chloride was already exemplified by oxidation of sulfides to sulfoxides [14]. Nevertheless, to confirm our hypothesis, we performed quantitative oxidation of thioamide 25 to amide 26 using sulfuryl chloride in dichloromethane at room temperature (Scheme 11).…”

A Mild and Efficient Synthesis of 3-Aminosubstituted Isothiazole S-Oxides and their 5-Sulfanylsubstituted Derivatives

“…A large number of procedures designed for carrying out the oxidation of sulfides to sulfoxides have been published, nevertheless most of them tried in this study resulted in low chemoselectivity and were unable to stop at the sulfoxide oxidation state [7 a-d ]. Most of the reagents tested (m-CPBA, HNO 3 /CH 3 COOH, H 2 O 2 , t-BuOOH/H 2 O/Ti(iPrO) 4 / DET, molybdenum (VI) oxodiperoxo complexes coated on silica gel, N-chloro-succinimide, oxone, MMPP) bore out this limitation [8][9][10] except sodium metaperiodate which reacted with 3-benzylaminoisothiazole (1a) affording 3-benzylaminoisothiazole 1-oxide (2a) in acceptable yields (56%) together with a small amount of 3-benzylaminoisothiazole 1,1-dioxide (3a)(14%) (Scheme 1) [11].…”

Synthesis and Properties of Chiral Pyrazolidines Derived from (+)‐Pulegone

“…The solvent was removed under reduced pressure and the oily residue purified by flash chromatography (EtOAc) yielding 18 (50 mg, 0.36 mmol, 71 %) as a colorless oil, which was in analytical data identical to the previously described compound. [28] Chiral HPLC analysis (Daicel Chiralcel AS-H, isopropanol/hexane = 7:3) revealed the product to be completely racemic.…”