Pyrimidotetrathiafulvalenes. 2. Trimethylsilylation of 5,-dioxo(4H, 6H)-1,3-dithiolo-[4,5-d]pyrimidine-2-selone and the use of the silylated product for the synthesis of 2,4-dioxopyrimidotetrathiafulvalenes

The trimethylsilylation of 5,7-dioxo(4H,6H)-1,3-dithiolo[4,5-d]pyrimidine-2-selone with bis(trimethylsilyl) acetamide enables pyrimido-tetrathiafulvalene derivatives to be prepared in benzene solution and increases the yield of the target compounds compared with the reaction of the unsilylated selone in DMF solution. The intermediate 2,4-bis(trimethyl-silyloxy)pyrimidotetrathisfulvalenes were sensitive to hydrolysis. The previously undescribed [2,4-dioxo(1H,3H)pyrimido]di-(methylthio)tetrathifulvalene has been obtained. The redox properties of the compounds obtained have been investigated by cyclic current-potential measurements.