Hydrazine hydrate (1:1) → 2-(2-Amino-5-fluorophenyl)acetohydrazide

HRID 1368477Notes

Reaction equation

HRID 1368477 reaction equation
[F:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6](=[O:11])[C:5]2=O.O.[NH2:14][NH2:15]>>[NH2:7][C:8]1[CH:9]=[CH:10][C:2]([F:1])=[CH:3][C:4]=1[CH2:5][C:6]([NH:14][NH2:15])=[O:11]

Participants

3

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 2365665-Fluoroisatin2×

Product 1

HCID 690577422-(2-Amino-5-fluorophenyl)acetohydrazide

Conditions

Temperature
110 °C

Procedure

Hydrazine hydrate (55%, 3000 mL) and 5-fluoroisatin (300 g) were heated to 100° C. An additional 5-fluoro-isatin (500 g) was added in portions (100 g) over 120 minutes with stirring. The mixture was heated to 110° C. and stirred for 4 hours. The mixture was cooled to room temperature and the solids collected by vacuum filtration to give crude (2-amino-5-fluoro-phenyl)-acetic acid hydrazide (748 g). The hydrazide was suspended in water (700 mL) and the pH of the mixture adjusted to <pH 3 with 12 N hydrochloric acid. The mixture was stirred for 12 hours at room temperature. The solids were collected by vacuum filtration and washed twice with water. The product was dried under vacuum to give 5-fluoro-1,3-dihydro-indol-2-one (600 g, 73% yield) as as a brown powder. 1H-NMR (dimethylsulfoxide-d6) δ 3.46 (s, 2H, CH2), 6.75, 6.95, 7.05 (3×m, 3H, aromatic), 10.35 (s, 1H, NH). MS m/z 152 [M+1].

Workup

  1. stirringstirred for 4 hours
  2. temperatureThe mixture was cooled to room temperature
  3. filtrationthe solids collected by vacuum filtration

Sources & evidence

ORD record
ord-50cc1f8118944d51b328a63f9b8ca569
Source dataset
uspto-grants-2003_06
Patent number
US06573293B2

Reaction notes

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