Novel synthesis process of 5H-dibenz [b,f] azepine and removal of chloroformyl protection group
A novel synthesis process of 5H-dibenz[b,f]azepine was studied.It is an important intermediate of 5H-dibenz[b,f]azepine-5-carboxamide,used in genetic engineering,materials science and so on.With 10,11-dihydro-5H-dibenz[b,f]azepine as raw material,5-chloroformyl-5H-dibenz[b,f]azepine was prepared by reflux with triphosgene in toluene,brominated with bromine in chlorobenzene,and dehydrobrominated at 130℃,finally,the title compound was obtained by removing chloroformyl group with NaOH in isopropanol with 80.4% overall yield.The optimal reaction conditions and yields (temperature,time,molar yield) were as follows: acyl chlorination,110℃,10 h,93.0%; bromination,dehydrobromination,100℃,2 h,130℃,5 h,88.0%; removal of chloroformyl group,40℃,3 h,98.2%. The melting point of the title compound was the same as literature reported,and its structure was confirmed by 1H NMR.The optimal technology condition to remove chloroformyl group as protection group and its application of protection for some amine compounds were also studied.