Synthesis and Reactions of Some New Thieno[2,3-C]pyridazine Derivatives

Abstract

The alkylation of 4-cyano-5,6-dimethylpyridazin-3(2H)-thione 3 with some halo compounds gave the S-alkylated products 4a–c , which upon treatment with ethanolic sodium ethoxide afforded the cyclized thienopyridazines 5a–c as products. Pyridazothienotriazines 6a–c were prepared by the treatment of compounds 5a–c with nitrous acid, while their reaction with triethyl orthoformate and with carbon disulfide gave the corresponding pyrimidothienopyridazines 7a–c , and 8a–c , respectively. S-alkylated products 9a–o were obtained by the reaction of 8a–c with some halo compounds.

Keywords:

• Pyridazine
• pyridazothienotriazine
• pyrimidothienopyridazine
• thieno[2,3-c]pyridazine