作者:Nico C. M. E. Barendse、Pieter A. M. van der Klein、Jan Verweij、Henk A. Witkamp、Wim J. van Zoest、Erik de Vroom
DOI:10.1055/s-1998-2018
日期:1998.2
The synthesis of the β-lactamase indicators Cefesone [(6R,7R)-3-(2,4-dinitrostyryl)-7-(phenylacetamido)ceph-3-em-4-carboxylic acid] and Nitrocefin [(6R,7R)-3-(2,4-dinitrostyryl)-7-(2-thienylacetamido)ceph-3-em-4-carboxylic acid] from tert-butyl (1S,6R,7R)-3-bromomethyl-1-oxo-7-(phenylacetamido)ceph-3-em-4-carboxylate is reported. Phosphonylation of the latter compound with triphenylphosphine gave the corresponding phosphonium derivative in 93% yield. Reduction followed by Wittig coupling with 2,4-dinitrobenzaldehyde gave a 1 : 12 mixture of E- and Z-isomers in 83% yield. The tert-butyl protecting group was removed with titanium tetrachloride to give Cefesone as the pure crystalline E-isomer in 63% yield. De-acylation was achieved by enzymatic hydrolysis in 77% yield. Finally the 2-thienylacetyl side chain was introduced to give crystalline Nitrocefin in 67% yield.
δ-内酰胺酶指示剂头孢松[(6R,7R)-3-(2,4-二硝基苯基)-7-(苯基乙酰氨基)头孢-3-em-4-羧酸]和硝基头孢烯[(6R,7R)-3-(2、(1S,6R,7R)-3-溴甲基-1-氧代-7-(苯基乙酰氨基)头孢-3-em-4-羧酸]和硝基蝶呤[(6R,7R)-3-(2,4-二硝基苯基)-7-(2-噻吩乙酰氨基)头孢-3-em-4-羧酸]。用三苯基膦对后一种化合物进行膦酰化,得到了相应的鏻衍生物,收率为 93%。还原后与 2,4-二硝基苯甲醛进行维蒂希偶联,得到了 1 : 12 的 E 型和 Z 型异构体混合物,收率为 83%。用四氯化钛去除叔丁基保护基,得到头孢西酮纯结晶 E 异构体,收率为 63%。用酶水解法进行脱酰化,收率为 77%。最后引入 2-噻吩乙酰基侧链,得到结晶的硝基西芬,收率为 67%。