Triazolo[4,5-d]pyrimidines. XI. Halogen-Metal Exchange Reaction of 5-Halo-3H-1,2,3-triazolo-[4,5-d]pyrimidines with Butyllithium.
作者:Ken-ichi TANJI、Hiroyuki KATO、Takeo HIGASHINO
DOI:10.1248/cpb.39.3037
日期:——
The amino group at the 5-position on the 3H-1, 2, 3-triazolo[4, 5-d]pyrimidine (triazolopyrimidine) ring was converted into a halogen atom by treatment with isopentyl nitrite in halomethanes in satisfactory yields.The 5-halotriazolopyrimidines not having a substituent at the 7-position reacted with butyllithium to give 7-butyl-6, 7-dihydro-3-phenyl-3H-1, 2, 3-triazolo[4, 5-d]pyrimidines by addition of butyllithium across the C7, N6-double bond. In the case of the 7-substituted 5-halotriazolopyrimidines, the halogen-metal exchange reaction proceeded and the resultant 5-lithio compound reacted with electrophiles to give the 5-substituted triazolopyrimidines.
通过在卤代甲烷中用亚硝酸异戊酯处理,将 3H-1,2,3-三唑并[4,5-d]嘧啶(三唑并嘧啶)环上 5 位的氨基转化为卤素原子,收率令人满意。 7-位不具有取代基的卤代三唑并嘧啶与丁基锂反应,通过加成得到7-丁基-6,7-二氢-3-苯基-3H-1,2,3-三唑并[4,5-d]嘧啶丁基锂穿过C7、N6-双键。在7-取代的5-卤代三唑并嘧啶的情况下,进行卤素-金属交换反应并且所得5-锂化合物与亲电子试剂反应,得到5-取代的三唑并嘧啶。