A method of regio-selectively synthesizing an imidazo-pyrimidine compound of formulae (XXa) or (XXb) comprising a step of coupling a first compound of formula XX-P1a or XX-P1b with a second compound of formula XX-P2. This annulation reaction between β-ethoxy acrylamides and phosphorylated aminoimidazoles to furnish imidazo[1,2-a]pyrimidin-amines relies on steering effects from endocyclic and exocyclic phosphorylated aminoimidazoles. The reaction furnishes either 2-amino or 4-amino constitutional isomers of imidazo[1,2-a]pyrimidines with good yields and ranges of 90:10 – 99:1 regio-selectivity. The reaction is useful in the synthesis of various tracer molecules used in the study of neurological conditions such as where R3 and R4 together with the imidazole ring atoms to which they are bonded form a phenyl ring and the products are substituted benzimidazopyrimidines. The reaction can be generalized to form imidazo[1,2-a]pyrimidines substituted at either of their 2- and 4- positions by alkoxy or thioalkyl groups.
一种选择性区域合成式(XXa)或(XXb)的
咪唑嘧啶化合物的方法,包括将式XX-P1a或XX-P1b的第一化合物与式XX-P2的第二化合物偶联的步骤。这种β-乙氧基
丙烯酰胺和
磷酸化
氨基
咪唑之间的环化反应,用于合成
咪唑[1,2-a]
嘧啶胺,依赖于内环和外环
磷酸化
氨基
咪唑的导向效应。该反应以良好的产率提供
咪唑[1,2-a]
嘧啶的2-
氨基或4-
氨基构型异构体,并具有90:10至99:1的选择性。该反应在合成用于研究神经系统疾病的各种示踪分子中很有用,例如当R3和R4与它们结合的
咪唑环原子形成苯环时,产物为取代苯基
咪唑嘧啶。该反应可推广为在其2-位和4-位之一被烷氧基或
硫代烷基基团取代的
咪唑[1,2-a]
嘧啶。