Electrophilic tetraalkylammonium nitrate nitration. II. Improved anhydrous aromatic and heteroaromatic mononitration with tetramethylammonium nitrate and triflic anhydride, including selected microwave examples.
A new one-pot nitration employing tetramethylammonium nitrate and trifluoromethanesulfonic anhydride in dichloromethane to provide a ready source of the nitronium triflate nitrating agent is presented. Rapid and selective nitration with a variety of aromatic and heteroaromatic substrates is achieved resulting in the synthesis of several novel organic compounds. A distinct advantage is the removal of undesired byproducts by aqueous workup. This very mild nitration permits large-scale syntheses and gives high isolated product yields that often require no further purification. This tetramethylammonium nitrate-based nitration also has been applied to microwave-assisted conditions, and the results with several compounds are outlined.
Shackelford
Scott A
SA
Pfizer Global Research and Development, La Jolla Laboratories, 3550 General Atomics Court, San Diego, California 92121-1194, USA. scott.shackelford@pfizer.com
Anderson
Mark B
MB
Christie
Lance C
LC
Goetzen
Thomas
T
Guzman
Mark C
MC
Hananel
Martha A
MA
Kornreich
Wayne D
WD
Li
Haitao
H
Pathak
Ved P
VP
Rabinovich
Alex K
AK
Rajapakse
Ranjan J
RJ
Truesdale
Larry K
LK
Tsank
Stella M
SM
Vazir
Haresh N
HN