1-Piperazineacetic acid, 4-(3,4,5-trimethoxycinnamoyl)-, ethyl ester, hydrochloride 23887-41-4 26219-22-7 4-(3',4',5'-Trimethoxycinnamoyl)-1-(ethoxycarbonylmethyl)piperazine hydrochloride 4-(3,4,5-Trimethoxycinnamoyl)-1-piperazineacetic acid ethyl ester hydrochloride