Synthesis of Camostat mesilate

Camostat mesilate was synthesized from 4-aminobenzoic acid by reaction with cyanamid to obtain 4-guanidinobenoic acid hydrochloride which reacted with 4-Hydroxyphenylacetyl dimethylaminoaceylmthylat was prepared from 4-hydroxyphenylacetic acid and N,N-dimethyl-2-chloride-acetamin.Compound structures were confirmed by MS,IR and ()~1H-NMR.The overall yield of the improved procedure was 56%.