Purines. VI. Reactions of 2-chloro- and 2-(methylsulfonyl)-9-phenyl-9H-purines with nucleophiles.
作者:KEN-ICHI TANJI、HARUMI KUBOTA、YUMI YAMAMOTO、TAKEO HIGASHINO
DOI:10.1248/cpb.35.4972
日期:——
The reactions of 2-chloro-9-phenyl-9H-purine (1) with sodium methoxide, ethoxide, and phenoxide as O-nucleophiles, with butylamine and piperidine as N-nucleophiles, and with sodium methylsulfide as an S-nucleophile, afforded 2-methoxy- (3a), 2-ethoxy- (3b), 2-phenoxy- (3c), 2-butylamino- (4a), 2-piperidino- (4b), and 2-methylthio-9-phenyl-9H-purine (5), respectively. Compound 1 also reacted with ethyl cyanoacetate and phenylacetonitrile as C-nucleophiles in the presence of sodium hydroxide in dimethyl sulfoxide to give ethyl H-cyano-9-phenyl-9H-purine-2-acetate (6a) and α, 9-diphenyl-9H-purine-2-acetonitrile (6b). However, 1 did not react with other active methylene compounds, ketones or potassium cyanide. On the other hand, 2- (methylsulfonyl) -9-phenyl-9H-purine (2), prepared easily from 1, smoothly reacted not only with active methylene compounds but also with ketones and potassium cyanide. When active methylene compounds, such as ethyl cyanoacetate and phenylacetonitrile, were used, 2 gave 6a and 6b in good yields. In the cases of ketones and potassium cyanide, the substitution reactions of 2 proceeded to give the corresponding 2-substituted 9H-purines (7 and 8a-d), as expected.
和甲基硫化钠作为 S-亲核体,分别得到 2-甲氧基- (3a)、2-乙氧基- (3b)、2-苯氧基- (3c)、2-丁氨基- (4a)、2-哌啶- (4b) 和 2-甲硫基-9-苯基-9H-嘌呤 (5)。在氢氧化钠存在下,化合物 1 还与氰基乙酸乙酯和苯乙腈作为 C-亲核物在二甲亚砜中发生反应,生成 H-氰基-9-苯基-9H-嘌呤-2-乙酸乙酯(6a)和α,9-二苯基-9H-嘌呤-2-乙腈(6b)。不过,1 与其他活性亚甲基化合物、酮或氰化钾都没有反应。另一方面,由 1 容易制备的 2-(甲磺酰基)-9-苯基-9H-嘌呤(2)不仅能与活性亚甲基化合物顺利反应,还能与酮类和氰化钾反应。当使用活性亚甲基化合物(如氰乙酸乙酯和苯乙腈)时,2 能以良好的产率得到 6a 和 6b。在使用酮和氰化钾的情况下,2 的取代反应按预期进行,得到相应的 2-取代 9H 嘌呤(7 和 8a-d)。