The synthetic process was improved by using sodium formate instead of sodium 2 - ethylhexanoate and yield of the modified method was also raised to 76 % with low consumption of 6 - apa comparing with the 70 % in the literature 该工艺路线使用甲酸钠代替异辛酸钠,减少了关键中间体6 -氨基青霉烷酸( 6 - apa )的耗用量,收率从文献的70 %提高到76 % 。