Reactions with 2-Methyl- and 2-Styryl-4-thiochromones
Diazoalkanes react with 2-methyl- and 2-styryl-4-thiochromones to yield the 1,3-dithiolanes 1 and/or ethylenes 2-4.The latter are cleaved with thionyl chloride to give the corresponding ketones, while on fusion with sulfur they afford the corresponding thioketones.By condensation with compounds containing active hydrogen, such as malononitrile and ethyl cyanoacetate, the 2-methyl- and 2-styryl-4-thiochromones yield the compounds 5.Oxidation of 2-methyl- and 2-styryl-4-thiochromones was accomplished by yellow mercury(II) oxide as well as with tetrahalo-o-benzoquinones to give the corresponding ketones.The biological activity of some selected comounds prepared during this work has been tested towards Gram-positive and Gram-negative bacteria.