The synthesis and biological evaluation of some caffeic acid amide derivatives: E-2-cyano-(3-substituted phenyl)acrylamides.

A series of caffeic acid amide derivatives 2-cyano-(3-substituted phenyl)acrylamides were synthesized via Knoevenogal condensation of substituted benzaldehydes with cyanoacetamides. The structure of compound 1f was determined as E-isomer by X-ray diffractive analysis. The biological screening tests in vitro showed that compound 1b has obvious inhibitory activities against human gastric carcinoma cell line BGC-823, human nasopharyngeal carcinoma cell line KB and human hepatoma cell line BEL-7402 with IC(50) values of 5.6 microg/mL, 13.1 microg/mL and 12.5 microg/mL, respectively. Some preliminary structure-activity relationships (SAR) were also proposed which may provide a direction for further study.