2026-09-25T15:05:11Z https://epublications.vu.lt/oai

oai:vu.lt:elaba:1938053 2026-07-06T23:26:43Z openaireNDLTDDRIVERDART-EUROPE

Alkilintų 5-cian-2-metilsulfanil-4(3H)-pirimidinonų sintezės ir ciklizacijos reakcijų tyrimas /Studies on the synthesis and cyclization reactions of alkylated 5-cyano-2-methylsulfanyl-4(3H)-pyrimidinones.Stankevičiūtė, Živilė,info:eu-repo/semantics/openAccess4(3H)pyrimidinone ; alkylation ; furo[2 ; 3-d]pyrimidine ; cyclizationThe cyclization reactions of initial ethyl (E)-2-cyano-3-(S-methylisothioureido)-2-propenoate under acid and basic catalysis conditions has been studied. It was determined that boiling in glacial acetic acid proceeds selectively and leads to formation of ethyl 4-amino-2-methylsulfanylpyrimidine-5-carboxylate, while ring closure in alkaline media gives rise to a mixture of 5-cyano-2-methylsulfanyl-4(3H)-pyrimidinone (major product), small amounts of ethyl 4-amino-2-methylsulfanylpyrimidine-5-carboxylate and uncyclisized products – ethyl 2-cyano-3-ureido-2-propenoates. Alkylation of 5-cyano-2-methylsulfanyl-4(3H)-pyrimidinone with 4-substituted ω- bromoacetophenones in the system CH3CN–K2CO3–[KI] has been investigated and influence of aromatic ring substituent for alkylation product distribution has been determined. The all three series of O-, N3- and N1-alkylated isomers have been isolated by means of fraction crystallization. Novel method for the synthesis of furo[2,3-d]pyrimidines by cyclization of of O-alkylated isomers – 2-methylsulfanyl-4-(4´-R-phenacyloxy)pyrimidine-5-carbonitriles – has been developed and functionalization (acetylation, oxidation, hydrolysis and hydrazinolysis) possibilities of synthesized 5-amino-6-(4´-R-benzoyl)-2-methylsulfanylfuro[2,3-d]pyrimidines has been examined.Institutional Repository of Vilnius UniversityMalinauskas, Albertasinfo:eu-repo/semantics/doctoralThesislit2010application/pdfhttps://epublications.vu.lt/object/elaba:1938053/1938053.pdfhttps://repository.vu.lt/VU:ELABAETD1938053&prefLang=en_US