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

HRID 1246151Notes

Reaction equation

HRID 1246151 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).

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-732fc6cee9a24bec8c0937741f706772
Source dataset
uspto-grants-2006_10
Patent number
US07125905B2

Reaction notes

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