摘要
Ⅰ. INTRODUCTION In a previous communication, the synthesis of some 2-oxo-3-indolyl derivatives has been reported. Ballantine et al. found that the reaction of ethyl 2-(2-oxo-3-indolylidene)-2-hydroxyacetate with propionic anhydride in the presence of pyridine furnished a red-brown crystalline product which was established as 3,4-dimethyl-2, 5-di-(N-propionyl-2-oxo-3-indolylidene)-2, 5-dihydrofuran. Similarly, treatment of isatin with ammonia furnished isamic acid.
