4-Aminophenylacetic acid → (4-Hydrazinophenyl)acetic acid hydrochloride

To a solution containing conc. HCl (76 ml) and 4-amino phenylacetic acid (10 g: 66 mmol) at 4° C. was added a solution of sodium nitrite (4.56 g; 55 mmol) in water (10 ml) dropwise, while maintaining the temperature at 0° to 4° C. The mixture was stirred for 30 minutes and added to a cold (0° C.) solution of SnCl2 (74.5 g 331 mmol) in conc. HCl (50 ml). The mixture was left to warm to room temperature overnight. The precipitate formed was filtered and washed withwater (50 ml), 50% aq. HCl (50 ml), water (50 ml) and ether (2×50 ml). The solid was dried in vacuo to give the product 13 g. M.pt. 220°-223° C. dec. MS. 166(M+) 151, 135, 121 NMR [360 Mz, 1H]ppm 3.5 (s,2H) 6.9 (d,2H) 7.1 (d, 2H), 10.7 (bs).

1. temperaturewhile maintaining the temperature at 0° to 4° C
2. waitThe mixture was left
3. customThe precipitate formed
4. filtrationwas filtered
5. washwashed withwater (50 ml), 50% aq. HCl (50 ml), water (50 ml) and ether (2×50 ml)
6. customThe solid was dried in vacuo

ORD record

ord-6aa4c2e7fd244af0b688a7441a3c0863

Source dataset

uspto-grants-1998_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05744466