苯溴马隆的合成及工艺改进

Improvement on the Synthetic Method of Benzobromarone

作者对原有的水杨醛和氯化丙酮为原料合成苯溴马隆的方法进行了改进 ,将第一步合成 2 乙酰基苯并呋喃和第二步合成 2 乙基苯并呋喃合并为一步 ,并用水蒸气蒸出 2 乙基苯并呋喃 ,不进一步纯化即进行下一步酰化反应 ;2 乙基 3 对羟基苯甲酰 苯并呋喃改用NaOH碱提法纯化 ,再用石油醚重结晶 ;最后一步溴化反应 ,运用在冰乙酸中缓慢滴加溴的方法 ,最终产品用V(石油醚 )∶V(甲苯 ) =4∶1混合溶剂重结晶 ,最终产品w(苯溴马隆 ) >99 5 % (HPLC法 )。作者给出了中间体的熔点或沸点及FT -IR ,最终产品结构由FT -IR ,1HNMR ,13 CNMR ,EI-MS确定。

The original synthetic method of benzobromarone with raw materials salicylal and chloroacetone is improved.Thus,preparation of 2 acetylbenzofuran and 2 ethylbenzofuran is combined in one step.2 Ethylbenzofuran separated by steam distillation is directly used in acylation without further purification to form 2 ethyl 3 ( p methoxybenzoyl) benzofuran.The intermediate 2 ethyl 3 ( p hydroxybenzoyl) benzofuran is purified with sodium hydroxide and recrystalized from ligroin.The target product is obtained by bromination in acetic acid and recrystalized in blended solvent V (ligroin)∶ V (toluene)=4∶1 with purity w(benzobromarone)>99 5% (by HPLC).Structures of the intermediates and final product are confirmed by FT-IR, 1HNMR, 13 CNMR and EI-MS.