Studies on the chemistry of thienoannelatedO,N- andS,N-containing heterocycles. 17. Preparation of 1H-thieno[2,3-b][1,4]thiazine-1-carboxarnides as smooth muscle relaxants

A new series of substituted thieno[1,4]thiazines with an urea moiety has been designed. The synthesis and results of replacement of the quinoline and indoline moieties of lead structure 1 are described. The key step in preparation was the substitution with 4-nitrophenyl chloroformate to obtain the required 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-channel-antagonistic and potassium-channel-opening activities.