Some new thiopyranoquinoline derivatives of possible biological activity

ABSTRACT

The interesting pharmacological activity of the quinoline derivatives led us to synthesis and study a new series of quinoline compounds fused with a thiopyrano moiety in a trial to obtain compounds of anticipated biological value. Thus, in continuation to our previous world, thiopyranoquinoline derivative 2, was chosen as starting material. This was obtained through the condensation of 2-methyl-4-chloroquinoline with thiosalicylic acid in presence of alcoholic sodium hydroxide solution to give 2-methyl-4- [7-chloroquinolinoyl] -2-carboxyphenylsulphide [1], followed by cyclization with polyphosphoric acid to yield 3-chloro-6-methyl-benzothiopyranoquinolin-7-one [2]. Furthermore, treatment a solution of 2 in acetic acid with hydrogen peroxide afforded the corresponding sulpone derivative 3. In addition, oxidation of 3 with selenium dioxide in dioxane solution yield the 3-chloro -6-carboxaldehyde - benzothiopyranoquinolin-7-one 12, 12-dioxide [4 a]. On the other hand compound 4 a was achieved directly through selenium dioxide oxidation of the thiopyrano derivative 2