ChemInform Abstract The allyloxy(allylthio)thienopyrimidones (III), prepared by allylation of the phenolates(thiolates) (I), react with bromine or iodine to give the tricyclic compounds (IV) mentioned in the title.
We demonstrated formerly that the N 1 -nucleophilic center of unsaturated thio ethers of thieno[2,3-d]pyrimidine could be brought into reactions of electrophilic heterocyclization [1,2]. The further study of bromination conditions of 2-hydroxy-4-oxo-3-phenylthieno[2,3d]pyrimidine allyl ether (I) revealed that notwithstanding the ratio and concentration of initial reagents and the time of the reaction the bromination of compound I in acetic acid gave rise to a fused system of salts of benzothienooxazolopyrimidinium II and III of angular structure.The bromination of allyl ether I followed by storage of the reaction mixture for 5 days at the use of low concentration of ether I (0.51.0%) and at the ratio of the initial compounds ether Ibromine equal to 1:1 (or 1:2) gave as a result monobromide II. In the event that the bromoheterocyclization is carried out at high concentration of ether I (5.010.0%) and at the ratio of the initial compounds ether Ibromine equal to 1:4 for 34 h the reaction yields tribromide III. We showed also that monobromide II formed at stirring tribromide III for 1 h in acetone or butanone. The direct bromination of salt II afforded tribromide III in a quantitative yield. In the 1 H NMR spectra of salts II and III lack the signals from the allyl fragment of initial ether I, and the resonances of a spin system ABX characteristic of the formed oxazolinium ring appear for monobromide II and tribromide III respectively as follows: a multiplet of the methine proton at 4.85 and 4.84 ppm; two doublet of 6 1 1 2 2 &+ +& &+ 6 1 1 2 2 &%U + %U B ,, , 6 1 1 2 2 &+&+ 2+ &+ %U 6 1 1 2 2 &+ %U B ,,, &+ &221D %U ,9 &+ &221D %U %U
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.