7,8,9,10-Tetrahydro-8-(trifluoroacetyl)-6,10-methano-6H-pyrazino[2,3-h][3]benzazepine (N-(trifluoroacetyl)varenicline) is an important pharmaceutical intermediate compound which is used in the preparation of varenicline. Varenicline is an oral smoking cessation aid drug. It works by blocking the pleasant effects of nicotine (from smoking) on the brain.