A Facile and Rapid Method for Preparation of Thiazine and Thiadiazine Derivatives by Sonication Technique

Abstract

Ultrasound accelerated synthesis of 2,3-(substituted)benzo-1,4-thiazino[5,6-b]-4H-9H-7-methyl-10-oxoquinolines (4), 7-substituted-2,2-dimethyl-2,3-dihydro-1H,10H-phenothiazin-4-one (5), 4-substituted-3,9, 10-trihydro-11-oxo-quinolino[2,3-b]-1,3,4-thiadiazino[2,3-d]-1,2,4-triazole (6), and 7,7-dimethyl-7,8-dihydro-3H,5H,6H-1,2,4-triazolo[3,4-b][1,3,4] benzothiadiazin-9-one (7) from carbostyril and dimedone using sulfur powder and iodine as a catalyst in THF is reported. The structures of the compounds have been elucidated on the basis of spectral and elemental analysis.

Synthesis of Heteroaryl Thiazolidinones and Azetidinones under Conventional and Ultrasonication Methods

“…The advantages of using ultrasound as an energy source to promote organic reactions include shorter reaction times and higher yields when compared with conventional thermal heating methods . The literature survey revealed the synthesis of different heterocycles viz., pyrazoles , thiazoles , isoxazoles , imidazolines , thiazolidinones , triazoles , thiazinanones , etc., by applying sonochemistry. The beneficial effects of ultrasonic irradiation and our interest to develop and to improve the methodologies in chemical processes especially where classical methods require prolonged reaction times prompted to plan for the synthesis of biologically potent thiazolidinones and azetidinone derivatives.…”

Bicyclic 5-6 Systems With One Bridgehead (Ring Junction) Nitrogen Atom: Four Extra Heteroatoms 2:2

“…The latter would undergo intramolecular Mannich-type reactions with in-situ generated vinylogous ketene acetals to form the two triazolothiadiazines rings (Scheme 49) 99. <Scheme 49 near here>Treatment of amino-triazole 266 with dimedone 267, sulphur powder and iodine as a catalyst under sonication produced fused system 268 in high yield (Scheme 51) 101. <Scheme 51 near here> Scheme 51 11.19.6.3.3(iii) construction of both rings (closure of the six-membered ring at the last step)…”