Synthesis of [3H]CI-980, ethyl[5-anino-1,2-dihydro-2(S)-methyl-3(3-[3H]phenyl)pyrido[3,4-b]jpyrazin-7-YL] carbamate isethionate salt, a tubulin-binding, antimitotic, broad-spectrum antitumor agent
作者:Helen T. Lee、Peter W. K. Woo
DOI:10.1002/jlcr.2580340103
日期:1994.1
[3H]CI-980 (10b) was synthesized in an eight-step sequence with an overall yield of 2.4%. Reaction of m-bromophenyl lithium (2) with N-ethoxycarbonyl-L-alanine gave the chiral ketone 3. Reduction of 3 with sodium borohydride followed by alkaline N-deprotection and condensation with ethyl 6-amino-4-chloro-5-nitro-2-pyridine carbamate (6) gave 7. Chromium trioxide oxidation of 7 followed by reductive cyclization with iron-acetic acid gave the key bromo intermediate 9. Palladium catalyzed 3H-hydrogenolysis of 9 gave the free base form of [3H]CI-980 (10a), which was converted to the isethionate salt (10b) before use.
[3H]CI-980 (10b) 是通过八步合成得到的,总产率为2.4%。m-溴苯基锂 (2) 与N-乙氧基羧基-L-丙氨酸反应生成手性酮3。用氢化钠还原3,然后进行碱性去保护,最后与乙基6-氨基-4-氯-5-硝基-2-吡啶 carbamate (6) 缩合得到7。用三氧化铬氧化7,随后用铁-醋酸还原环化得到关键溴中间体9。催化剂为钯的3H-氢解反应将9转化为[3H]CI-980 (10a) 的游离碱形式,之后转化为异雄脱盐 (10b) 以备使用。