作者:Bryan Li、F. Bi、Richard Buzon、Ming Kang、Robert Oliver、John Sagal、Lacey Samp、Daniel Walker、Zhijun Zhang
DOI:10.1055/s-0030-1258481
日期:2010.9
practical synthesis of 4-amino-2-(trifluoromethyl)-nicotinic acid is described. 2-(Trifluoromethyl)pyridine was lithiated using lithium 2,2,6,6-tetramethylpiperidide (LTMP) in the presence of 1,3-dimethyl-2-imidazolidinone (DMI) and followed by CO 2 quench to give the C-3 carboxylation product. Subsequent directed C-4 lithiation of carboxylation product afforded 4-iodo-2-(trifluoromethyl)nicotinic acid
描述了 4-氨基-2-(三氟甲基)-烟酸的实际合成。在 1,3-二甲基-2-咪唑烷酮 (DMI) 存在下使用 2,2,6,6-四甲基哌啶 (LTMP) 锂化 2-(三氟甲基) 吡啶,然后用 CO 2 淬灭,得到 C-3羧化产物。随后羧化产物的定向 C-4 锂化得到 4-iodo-2-(三氟甲基) 烟酸,其在 Pd 催化条件下与氨基甲酸叔丁酯偶联,然后进行 Boc 脱保护,以四步和 50 步得到标题产物% 总产率。