K. Pillai, G. Diamantidis, L. Duncan
Mar 1, 1994
Citations
0
Influential Citations
8
Citations
Journal
Journal of Organic Chemistry
Abstract
The syntheses of 2,4,6-triiodo-1,3-benzenedicarboxamide analogs, (12c), (12e), and (17c), of interest as X-ray diagnostic agents and in which the 5 position is linked to the N atom of a 4-(hydroxymethyl)-oxazoli- din-2-one moiety, are described. The heterocycle was built from suitably protected 5-amino-2,4,6-triiodo-1,3-benzenedicarboxylic acid derivati- ves by a three-step procedure consisting of (1) phosgene treatment to obtain the corresponding isocyanates, (2) phenylmercuric chloride-cata- lyzed addition of glycidol (10) resulting in glycidyl carbamates, and (3) pyridine-catalyzed intramolecular N-alkylation, followed by depro- tection, to obtain the oxazolidin-2-ones. The intramolecular N-alkyla- tion reaction was highly regioselective and was not appreciably accom- panied by O-alkylation products under the experimental conditions emp- loyed. These highlt congested benzenoid compounds exhibited intersting NMR spectral features due to atropisomerism arising from hindrance to free rotation about the three single bonds that link the aromatic moiety to the N-containing functionalities