Part 1: Synthesis of Polyfused Heterocyclic Systems Derived From 3-Phenyl-5,6,7,8-tetrahydro[1,2,4]triazolo[3,4- b ][1,3,4]thiadiazepine-6,8-dione

Abstract

3-Phenyl-5,6,7,8-tetrahydro[1,2,4]triazolo[3,4- b ][1,3,4]thiadiazepine-6,8-dione ( 1 ) was condensed with o -aminothiophenol, 2-amino-ethanol or cystamine to afford compounds 2-4 respectively. Treatment of compound 1 with dimethylthiomethylenemalononitrile yielded the corresponding pyrano[3,2- f ][1,2,4]triazolo[3,4- b ]-[1,3,4]thiadiazepine derivative 5 . 7-[5-Amino-1,3-dithiolan-2-ylidene]-3-phenyl-5,6,7,8-tetrahydro[1,2,4]triazolo[3,4- b ][1,3,4]thiadiazepine-6,8-dione ( 6 ) was obtained by treating compound 1 with CS 2 and chloroacetonitrile. Thiation of compound 1 gave the corresponding thioanalog 7 , which in turn was condensed with malononitrile to give 3-phenyl-5,6,7,8-tetrahydro[1,2,4]triazolo[3,4- b ][1,3,4]thiadiazepine-6-one-8-ylidenemalononitrile ( 8 ). On treating compound 8 with benzaldehyde or p -nitrobenzaldehyde, pyrano[1,2,4]triazolo[1,3,4]thiadiazepin derivatives 9a , b , respectively, were obtained. Compound 8 was treated with CS 2 and methyl iodid to give the corresponding dithiomethylmethylene derivative 10 which was subjected to react with aniline to give pyrido[1,2,4]triazolo[1,3,4]thiadiazepine derivative 11 . Compound 8 was treated with 3-aminopyridine, o -aminothiophenol, or o -phenylenediamene to yield compounds 12 and 13a , b respectively. Finally, tertiary amines or activated phenols were condensed with compound 8 to yield compounds 14 and 15a , b respectively.

Keywords:

• Cs 2
• Malonyl Dichloride
• Ptc
• Thiadiazepine
• Triazole