Hydrazine hydrate (1:1) → 5-Fluoronicotinohydrazide

HRID 868342Notes

Reaction equation

HRID 868342 reaction equation
[F:1][C:2]1[CH:3]=[N:4][CH:5]=[C:6]([CH:12]=1)[C:7](OCC)=[O:8].O.[NH2:14][NH2:15]>O>[F:1][C:2]1[CH:12]=[C:6]([C:7]([NH:14][NH2:15])=[O:8])[CH:5]=[N:4][CH:3]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 211184Ethyl 5-fluoronicotinate

Product 1

HCID 3514635-FluoronicotinohydrazideYield 83%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 6.7 g of ethyl 5-fluoronicotinate (cf. U.S. Pat. No. 3,637,714) and 6.0 g of hydrazine monohydrate is stirred at 110° C. for 2 hours. After cooling, 30 ml of cold water is added, and the precipitate is collected and washed with cold water to give 5.1 g of crude 5-fluoro-3-pyridinecarbohydrazide. To a stirred mixture of 5.1 g of the hydrazide in 40 ml of pyridine, 6.9 g of p-toluenesulfonyl chloride is added slowly. After the mixture becomes a clear solution, the remaining pyridine is distilled off under reduced pressure, and 30 ml of water is added. The resulting precipitate is collected and washed with water to give 6.6 g of the crude p-toluenesulfonyl derivative. The product is added to 40 ml of ethylene glycol at 120° C., and to the mixture is added with stirring 6.5 g of anhydrous sodium carbonate. The reaction mixture is stirred at 160° C. for 10 minutes and cooled, and 50 ml of water is added. The mixture is extracted with three 100-ml portions of diethyl ether. The combined extracts are dried over magnesium sulfate and concentrated to give 1.1 g of crude 5-fluoro-3-pyridinecarbaldehyde.

Workup

  1. temperatureAfter cooling
  2. customthe precipitate is collected
  3. washwashed with cold water

Sources & evidence

ORD record
ord-2ec4161ebffd453f970a3b879f6c5f9b
Source dataset
uspto-grants-1988_10
Patent number
US04778796

Reaction notes

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