2-Amino-4-(2-nitrophenyl)butyric acid hydrochloride → 2-Amino-4-(2-aminophenyl)butyric acid

Alternatively, a solution of 2-amino-4-(2-nitrophenyl)butyric acid hydrochloride (2.5 g) in water (200 ml) was hydrogenated at room temperature and atmospheric pressure, using 10% Pd-C (0.5 g) as catalyst. After uptake of hydrogen ceased, the catalyst was filtered off, and the filtrate evaporated to dryness. The residue was dissolved in water (50 ml) and the pH adjusted to 7 by the addition of 10% sodium hydroxide. The solid was filtered off, washed with water, and dried to give 2-amino-4-(2-aminophenyl)butyric acid. A solution of the 2-amino-4-(2-aminophenyl)butyric acid (1.0 g), hexamethyldisilazane (5.4 g), and chlorotrimethylsilane (0.1 g) in xylene (125 ml) was refluxed for 65 hours. The reaction mixture was cooled, poured into ethanol (200 ml) and evaporated under reduced pressure. Water (100 ml) was added, and the solution extracted with dichloromethane (2×125 ml). The combined dichloromethane solutions were washed with water (50 ml), dried over magnesium sulfate, and evaporated under reduced pressure to give 3-amino-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one as above.

1. customwas hydrogenated at room temperature
2. filtrationthe catalyst was filtered off
3. customthe filtrate evaporated to dryness
4. dissolutionThe residue was dissolved in water (50 ml)
5. additionthe pH adjusted to 7 by the addition of 10% sodium hydroxide
6. filtrationThe solid was filtered off
7. washwashed with water
8. customdried

ORD record

ord-a9b03aa2e25942bca597fa3a7c7b3cf2

Source dataset

uspto-grants-1986_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04575503