Synthesis of new polyfunctional 5,6,7,8-tetrahydroimidazo-[1,5-c]pyrimidin-5-ones by the aza-Wittig reaction followed by intramolecular cyclization and 1,3-prototropic shift

Discovery of Potent and Highly Selective A2B Adenosine Receptor Antagonist Chemotypes

“…The synthetic strategy employed to obtain the target 3,4-dihydropyridin-2(1H)-ones 17a−h is depicted in Scheme 1. Following a previously described procedure, 37 d]pyrimidine-2,5-diones 18 were obtained by submitting 28 to an eliminative cyclization in dimethylformamide, 38 whereas pyrrolo [3,4-d]pyrimidine-2,5-diones 19 were readily obtained by microwave heating of 28 with ethylamine. 39 As for the previous target structures (17−19), the ligands bearing heterocycles fused to the 2,3-positions of the pyrimidine core (20−22) were assembled by a threecomponent Biginelli condensation (Scheme 3) 40,41 that employs heterocyclic surrogates of the urea component [i.e., 2-aminoimidazole (29a), 2-amino-1,2,4-triazole (29b), or 2aminobenzimidazole (29c)] as key precursors in combination with the carbaldehydes (25a−d) and the corresponding alkyl acetoacetates (24a,b).…”

“…5 General Procedure for the Synthesis of 3,4-Dihydrofuro[3,4d]pyrimidine-2,5(1H,7H)-diones18a−d. 38 A solution of the corresponding 6-chloromethyl-3,4,-dihydropyrimidin-2(1H)-one 28a−d, (5 mmol) in DMF (8 mL) was stirred with orbital stirring at 150 °C for 24 h. After completion of the reaction, as indicated by TLC, the solvent was removed in vacuum and the obtained oily residue was poured onto crushed ice. The solid separated was filtered under suction and then purified by column chromatography on silica gel.…”

Manuseio E Armazenamento De Produtos Químicos: Diagnosticando Conhecimentos

“…A hibridização molecular é uma estratégia de construção de moléculas baseada na conexão de duas ou mais unidades farmacofóricas para a formação de protótipos moleculares bioativos. Farmacóforos são fragmentos moleculares defi nidos a partir de um conjunto de características estéricas e eletrônicas que garantam a interação supramolecular com um alvo biológico específi co (WERMUTH et al, 1998 (LEBED et al, 2009). A reação foi efetuada a 50ºC por um período de 48h e as cloro-DHPMs 7a-c puderam ser obtidas em rendimentos razoáveis de 67-72%.…”

Síntese De Compostos Híbridos Chalconasdihidropirimidinonas via Reação De Huisgen

“…1. A reação de Biginelli foi realizada utilizando ácido acético como solvente e catalisador (LEBED et al, 2009). A reação foi efetuada a 50ºC por um período de 48h e as cloro-DHPMs 7a-c puderam ser obtidas em rendimentos razoáveis de 67-72%.…”