[CH3:1][C:2]1[C:9]([F:10])=[C:8]([F:11])[C:5]([C:6]#[N:7])=[C:4]([F:12])[C:3]=1[F:13].[C:14]([OH:17])(=[O:16])[CH3:15].[H][H]>[Pd].O>[C:14]([O-:17])(=[O:16])[CH3:15].[CH3:1][C:2]1[C:3]([F:13])=[C:4]([F:12])[C:5]([CH2:6][NH3+:7])=[C:8]([F:11])[C:9]=1[F:10]A mixture of 30.0 g 4-methyl-2,3,5,6-tetrafluorobenzonitrile (0.1556 mol), 0.3 g wetting agent (Nopco 8050), 1.40 g palladium on carbon Johnson Matthey type 58 catalyst, 150 g glacial acetic acid and 217 g water was stirred under 5 barg hydrogen pressure. The reaction temperature was allowed to increase from an initial 5° C. to 30° C. over 3 hours, the reaction then being continued for a further 2 hours at which time no further hydrogen was seen to be taken up. The catalyst was removed by filtration and the solid residue washed with dichloromethane. A sample of the aqueous filtrates were evaporated to dryness and further dried under vacuum at 40° C. to give the product 4-methyl-2,3,5,6-tetrafluorobenzylammonium acetate as a white solid, melting point 113-114° C. NMR (200 MHz, D2O); d 1.90 (3H, s), 2.17 (2H, m), 2.24 (3H, t, J=2.2 Hz). This solid was than used as a technical standard to estimate the strength of the remaining solution. The solution was estimated to be 3.84% 4-methyl-2,3,5,6-tetrafluorobenzylamine. This gave an overall yield. based on 583.1 g of filtrates isolated yield of 73.8%. A sample of the free amine was isolated by basification of the reaction mass. NMR (200 MHz, D2O): d 2.08 (2H, m), 2.17 (3H, t, J=2.2 hz), 3.86 (2H, s)
読み込み中…
