Sulfuric Acid → Ethyl 3-(2,4-difluorophenyl)prop-2-enoate

HRID 974391Notes

Reaction equation

HRID 974391 reaction equation
[F:1][C:2]1[CH:8]=[C:7]([F:9])[CH:6]=[CH:5][C:3]=1N.S(=O)(=O)(O)O.N([O-])=O.[Na+].[C:19]([O:23][CH2:24][CH3:25])(=[O:22])[CH:20]=[CH2:21]>C(O)(=O)C.O.C1(C=CC(=O)C=CC2C=CC=CC=2)C=CC=CC=1.C1(C=CC(=O)C=CC2C=CC=CC=2)C=CC=CC=1.[Pd]>[F:1][C:2]1[CH:8]=[C:7]([F:9])[CH:6]=[CH:5][C:3]=1[CH:21]=[CH:20][C:19]([O:23][CH2:24][CH3:25])=[O:22]

Participants

8

Reactant 4

HCID 1118Sulfuric AcidHCID 8821Ethyl AcrylateHCID 97092,4-DifluoroanilineHCID 23668193Sodium Nitrite

Product 1

HCID 53395691Ethyl 3-(2,4-difluorophenyl)prop-2-enoate

Reagents, catalysts & solvents 3

HCID 1542701,5-Diphenylpenta-1,4-dien-3-one;palladiumCatalystHCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

51.6 g (0.40 mol) or 2,4-difluoroaniline are dissolved in 240 ml of glacial acetic acid. 45 ml (0.80 mol) of concentrated sulfuric acid are added slowly with cooling. The white suspension is diazotized at 12°-15° C. using a solution of 28.0 g (0.406 mol) of sodium nitrite in 70 ml of water. 1.2 g (0.0044 mol) of palladium bis(1,5-diphenyl-1,4-pentadien-3-one) (lit.: M. F. Rettig et al., Inorg. Synth. 17 (1977), 134) are added to the resultant yellow solution at 45° C. 40.5 g (0.405 mol) of ethyl acrylate are then added dropwise. The reaction is slightly exothermic, and the temperature slowly rises to about 60° C. The reaction mixture is stirred overnight with falling temperature and then poured into about 600 ml of ice-water. The waxy precipitate is extracted with 500 ml of diethyl ether. The ether phase is separated off, washed several times with ice-water and then dried using sodium sulfate. The ether is removed by distillation on a vacuum rotary evaporator. 51.2 g (60% of theory) of a waxy crystalline product which, after recrystallization from petroleum ether, melts at 40°-40.5° C. are obtained.

Workup

  1. temperaturewith cooling
  2. customis diazotized at 12°-15° C.
  3. customslowly rises to about 60° C
  4. extractionThe waxy precipitate is extracted with 500 ml of diethyl ether
  5. customThe ether phase is separated off
  6. washwashed several times with ice-water
  7. customdried
  8. customThe ether is removed by distillation on a vacuum rotary evaporator
  9. custom51.2 g (60% of theory) of a waxy crystalline product which, after recrystallization from petroleum ether, melts at 40°-40.5° C.
  10. customare obtained

Sources & evidence

ORD record
ord-3ce316eaa7264875bd10b824dbaa80cd
Source dataset
uspto-grants-1991_11
Patent number
US05068371

Reaction notes

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