A series of n-butylphthalide derivatives were designed and synthesized. The in vitro activities of these compounds were evaluated by a resting tension of isolated rat thoracic aorta ring assay. Compounds 4g and 4i were found to be more active than n-butylphthalide. ... A series of n-butylphthalide derivatives were designed and synthesized. The activities of these compounds were evaluated. ... Cardiovascular and cerebrovascular disorders are the main reason ...