Studies on the chemistry of thienoannelated O,N- and S,N-containing heterocycles. 17. Preparation of 1H-thieno[2,3-b][1,4]thiazine-1-carboxamides as smooth muscle relaxants

A new series of substituted thieno[1,4]thiazines with an urea moiety has be en designed. The synthesis and results of replacement of the quinoline and indoline moieties of lead structure 1 are described. The key step in prepar ation was the substitution with 4-nitrophenyl chloroformate to obtain the r equired reactivity for substitution with diamines. Structural modifications of the amino side chain with the aim of finding tissue specific compounds were carried out. Pharmacological testings explored the presumed calcium-ch annel-antagonistic and potassium-channel-opening activities.