REGIOSELECTIVE NITRATION OF 1-ACYL-4-METHOXYINDOLINES LEADS TO EFFICIENT SYNTHESIS OF A PHOTOLABILE l-GLUTAMATE PRECURSOR

ABSTRACT

Different nitrating reagents give different ratios of 5- and 7-nitro isomers of the title indolines. The best ratio of the 7-nitro isomer was obtained with claycop–acetic anhydride, and these conditions were particularly useful for preparation of a photolabile l-glutamate derivative.

Keywords:

• Aromatic nitration
• Caged l-glutamate
• Claypop
• Nitroindolines

ACKNOWLEDGMENT

We are grateful to Dr. G. Kelly for recording NMR spectra, to Dr. K. Welham for mass spectrometric measurements and to the MRC Biomedical NMR Centre for access to facilities. GP was supported by NIH Grant HL19242.