Triazolo[4,5-d]pyrimidines. X. Halogen-Metal Exchange Reaction of 7-Halo-3-phenyl-3H-1,2,3-triazolo[4,5-d]pyrimidines with Butyllithium.
作者:Ken-ichi TANJI、Hiroyuki KATO、Takeo HIGASHINO
DOI:10.1248/cpb.39.2793
日期:——
The amino group at the 7-position on the 3H-1, 2, 3-triazolo[4, 5-d]pyrimidine ring was converted into halogen atoms by treatment with isopentyl nitrite in halomethanes, in satisfactory yields. The halogen-metal exchange reaction between 7-iodo-3-phenyl-3H-1, 2, 3-triazolo[4, 5-d]pyrimidine (2) and butyllithium in the presence of N, N, N', N'-tetramethylethylenediamine proceeded, giving the 7-lithio compound (9). The lithio compound (9) reacted smoothly with electrophiles to give the corresponding 7-substituted compounds (15-18). On the other hand, the reaction of 7-chloro-3-phenyl-3H-1, 2, 3-triazolo[4, 5-d]pyrimidine (1) with butyllithium gave the ring fission product, 5-amino-1-phenyl-1H-1, 2, 3-triazole-4-carbonitrile (14).
通过在卤代甲烷中使用亚硝酸异戊酯处理,3H-1,2,3-三唑并[4,5-d]嘧啶环上位于 7 位的氨基被转化为卤素原子,产率令人满意。在 N,N,N',N'-四甲基乙二胺存在下,7-碘-3-苯基-3H-1,2,3-三唑并[4,5-d]嘧啶(2)与丁锂发生卤金属交换反应,得到 7-硫代化合物(9)。硫代锂化合物 (9) 与亲电物顺利反应,得到相应的 7-取代化合物 (15-18)。另一方面,7-氯-3-苯基-3H-1,2,3-三唑并[4,5-d]嘧啶(1)与丁锂反应得到了环裂变产物 5-氨基-1-苯基-1H-1,2,3-三唑-4-甲腈(14)。