Ring transformation of condensed pyrimidines by enamines and ynamines. Formation of condensed pyridines and condensed diazocines.
作者:Akira MIYASHITA、Naokata TAIDO、Susumu SATO、Ken-ichi YAMAMOTO、Hitoshi ISHIDA、Takeo HIGASHINO
DOI:10.1248/cpb.39.282
日期:——
A [4+2]-cycloaddition of quinazoline (2) and the 3H-1, 2, 3-triazolo[4, 5-d]pyrimidine 4 with enamines 1a-e resulted in ring transformation into the quinolines, 3a and 3c, and the 3H-1, 2, 3-triazolo[4, 5-b]pyridines, 5a-e, respectively. Similarly, the ynamine 13a cycloadded to 2 and its 4-cyano derivative 6, giving the quinolines, 14a and 14b, respectively.On the other hand, the 3H-1, 2, 3-triazolo[4, 5-d]pyrimidines 4, 15, 8, 16, 17, 18, and 19 underwent [2+2]-cycloaddition with the ynamine 13a, resulting in ring transformation into the corresponding 3H-1, 2, 3-triazolo[4, 5-d]-[1, 3]diazocines 21a-27. The 7-methoxy derivative 20, the 4-methoxy- and 4-cyano-1H-pyrazolo[3, 4-d]pyrimidines, 30 and 31, and the 6-cyano-9H-purine 36 also underwent [2+2]-cycloaddition with 13a to give the corresponding 3H-1, 2-3-triazolo[4, 5-b][1, 5]diazocine 28, 1H-pyrazolo[3, 4-b][1, 5]diazocines, 32 and 33, and 3H-imidazo[4, 5-b]-[1, 5]diazocine 37, respectively.The structures of the 1, 3- and 1, 5-diazocines, 21a and 28, were determined by X-ray crystallography.
喹唑啉(2)和3H-1, 2, 3-三氮杂[4, 5-d]嘧啶(4)与烯胺(1a-e)进行[4+2]环加成反应,导致环转化为喹啉(3a和3c)和相应的3H-1, 2, 3-三氮杂[4, 5-b]吡啶(5a-e)。类似地,烯氨(13a)与2及其4-氰基衍生物6进行环加成,分别生成喹啉(14a和14b)。另一方面,3H-1, 2, 3-三氮杂[4, 5-d]嘧啶(4、15、8、16、17、18和19)与烯氨(13a)发生[2+2]环加成反应,导致环转化为相应的3H-1, 2, 3-三氮杂[4, 5-d]-[1, 3]二氮环(21a-27)。7-甲氧基衍生物20、4-甲氧基和4-氰基的1H-吡唑[3, 4-d]嘧啶(30和31)以及6-氰基-9H-嘌呤(36)也与13a发生[2+2]环加成,分别生成相应的3H-1, 2-3-三氮杂[4, 5-b][1, 5]二氮环(28)、1H-吡唑[3, 4-b][1, 5]二氮环(32和33)和3H-咪唑[4, 5-b]-[1, 5]二氮环(37)。1, 3-和1, 5-二氮环(21a和28)的结构通过X射线晶体学确定。