An Efficient Route to Pyridazino[4, 3‐e][1, 3, 4]thiadiazines

Abstract

Some new 3‐(alkylsulfanyl)‐7‐chloro‐1‐phenyl‐1H‐pyridazino [4,3‐e][1,3,4]thiadiazine were synthesized by treatment of the alkyl‐2‐phenylhydrazinecarbodithioates with 4‐bromo‐3,6‐dichloropyridazine in alkaline acetonitrile. Orientation of the reaction has been determined by X‐ray crystallography technique. The chlorine atom on the number 7 position of these products was replaced by secondary amines at reflux condition.

Convenient synthesis of novel pyrimido[4,5‐b][1,5]benzothiazepines

“…[2] These findings encouraged scientists to prepare pyrimido [4,5-b] [1,4]benzothiazepines by (a) condensation of 5-aminopyrimidine-4-thiol with 2-chlromethylbenzoates [44] and (b) 4-chloropyrimidin-5-amine on the Bischler− Napieralski-type reactions [45] as a potential biologically active scaffold. Prompt by these findings and in continuation of our studies on the synthesis of N, S containing heterocycles [46][47][48][49][50][51][52][53] we decided to prepare a group of pyrimido [4,5-b] [1,5]benzothiazepine derivatives, which have been largely overlooked as a class of pyrimidobenzothiazepine.…”