Nitration and Nitrocompounds
Abstract
In the course of studying new superacid system in nitration we evaluated the nitric-tetratriflatoboric acid system HNO3-HB(O3SCF3)4 for its nitrating ability of aromatics. Tetratriflatoboric acid, HB(O3SCF3)4 was conveniently prepared in situ from triflic acid (excess) and boron trichloride and could be used without any workup. Nitration of benzene, toluene, fluorobenzene, chlorobenzene, anisole and naphthalene was studied with HNO3-HB(O3SCF3)4 in methylene chloride solution at -30 deg C and at room temperature. the new superacidic nitration of toluene gave very low (1%) meta nitration both at - 30 deg C and at room temperature. At the same time the ortholpara isomer ratio is also lower than in most studied nitronium ion nitrations, indicating ion pairing or association with bulky tetratriflatoborate anion. Similarly high regio(positional) selectivity was found in nitration of the other aromatics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1991
- Accession Number
- ADA243380
Entities
Organizations
- University of Southern California