Urea → (2,3-Difluorophenyl)hydrazine

HRID 256223Notes

Reaction equation

HRID 256223 reaction equation
[F:1][C:2]1[C:8]([F:9])=[CH:7][CH:6]=[CH:5][C:3]=1[NH2:4].[N:10]([O-])=O.[Na+].NC(N)=O>O.Cl>[F:1][C:2]1[C:8]([F:9])=[CH:7][CH:6]=[CH:5][C:3]=1[NH:4][NH2:10]

Participants

6

Reactant 3

HCID 1176UreaHCID 782782,3-DifluoroanilineHCID 23668193Sodium Nitrite

Product 1

HCID 12891832(2,3-Difluorophenyl)hydrazineYield 98.5%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolvent2×HCID 962WaterSolvent

Procedure

In each of two flasks, 775 mmol (100 g) of 2,3-difluoroaniline were added to 2 L of concentrated hydrochloric acid at -15° C. and treated dropwise with a solution of 852 mmol (58.9 g) of sodium nitrite in 500 mL of water. Ten minutes after the addition, the reaction was treated with 930 mmol (55.8 g) of urea. This was followed by rapid addition of a solution of stannous chloride dihydrate (968 mmol, 220 g) in 700 mL of concentrated hydrochloric acid precooled to -50° C. After 20 minutes, the solid from both reactions was filtered and combined. It was put into 3 L of 1M NaOH (aq) and extracted wtih 4×500 mL of ether. The extracts were combined, dried over MgSO4 and concentrated to afford 110 g of 2,3-difluorophenylhydrazine (763 mmol, 49%).

Workup

  1. additionTen minutes after the addition
  2. customprecooled to -50° C
  3. filtrationthe solid from both reactions was filtered
  4. extractionextracted wtih 4×500 mL of ether
  5. dry with materialdried over MgSO4
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-b51bd76d6aaa467da424d09241ecea62
Source dataset
uspto-grants-1987_10
Patent number
US04701533

Reaction notes

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