Download (4Mb) - Etheses - Saurashtra University

Part – B Studies on isatin derivatives…..
B.5 N-ACYLATION ON ISATIN
The synthesis of N-acylisatins under a variety of conditions has been
described using acyl chlorides or anhydrides under reflux. The reaction may
be performed without additives 205 or by using perchloric acid in benzene,
triethylamine in benzene, 103 pyridine in benzene, 206 or triethylamine in
chloroform 207, 208 as catalysts; or by conversion of isatin to sodium isatide
using NaH in toluene under reflux and subsequent reaction with acyl
chlorides. 144
The use of diacyl chlorides such as oxalyl 209 , octanedioyl or
nonanedioyl chlorides 210 , yields bisacylisatins. Attempts to use 2, 2dimethylmalonyl
chloride to furnish 2, 2-dimethylmalonyl-bis-isatin failed, and
led instead to an unusual tricyclic compound which was characterized by
spectroscopic methods and by X-ray diffraction. 211 (Fig. B.1.3)
Fig. B.1.3
Other complex products have been obtained from the reaction of isatin
and acetic anhydride in the presence of pyridine. 212 (Fig. B.1.4)
Similarly, dimers may be formed in the acetylation of indolylglyoxalates
with acetic anhydride in pyridine. 213 (Fig. B.1.5)
Many authors 214-230 have reported N-acylation or N-acetylation on
isatin.
Department of Chemistry, Saurashtra University, Rajkot-360 005 118