title: Highly Regioselective Nitration Reactions Provide a Versatile Method of Functionalizing Benzocycloheptapyridine Tricyclic Ring Systems: Application toward Preparation of Nanomolar Inhibitors of Farnesyl Protein Transferase.
abstract: A comprehensive study of nitration reaction of azatricyclic systems has been carried out. Whereas classical nitrations using KNO(3)-H(2)SO(4) at low temperatures gave nitrated products mainly at the 9-position, use of tetrabutylammonium nitrate-trifluoroacetic anhydride (TBAN-TFAA) resulted in exclusive nitration of the 3-position in the case carbamates 1, and 4-6 and the tricyclic ketone 7. These 3-nitro tricyclic derivatives have been valuable intermediates for the preparation of the very potent farnesyl protein transferase inhibitors such as the tricyclic pyridyl acetamide 32 and other new analogues.
authors.affiliation: Schering-Plough Research Institute, Department of Chemistry, 2015 Galloping Hill Road, Kenilworth, New Jersey, 07033.
authors.forename: F. George
authors.initials: FG
authors.lastname: Njoroge
authors.forename: Bancha
authors.initials: B
authors.lastname: Vibulbhan
authors.forename: Patrick
authors.initials: P
authors.lastname: Pinto
authors.forename: Tze-Ming
authors.initials: TM
authors.lastname: Chan
authors.forename: Rebecca
authors.initials: R
authors.lastname: Osterman
authors.forename: Stacy
authors.initials: S
authors.lastname: Remiszewski
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Del Rosario
authors.forename: Ronald
authors.initials: R
authors.lastname: Doll
authors.forename: V.
authors.initials: V
authors.lastname: Girijavallabhan
authors.forename: Ashit K.
authors.initials: AK
authors.lastname: Ganguly