Iodine → 4-bromo-4'-chloro-N-methylacetoacetanilide

HRID 1388985Notes

Reaction equation

HRID 1388985 reaction equation
[Cl:1][C:2]1[CH:15]=[CH:14][C:5]([N:6]([CH3:13])[C:7](=[O:12])[CH2:8][C:9]([CH3:11])=[O:10])=[CH:4][CH:3]=1.[Br:16]Br.II.O>C(O)(=O)C>[Br:16][CH2:11][C:9](=[O:10])[CH2:8][C:7]([N:6]([CH3:13])[C:5]1[CH:4]=[CH:3][C:2]([Cl:1])=[CH:15][CH:14]=1)=[O:12]

Participants

6

Reactant 4

HCID 807IodineHCID 962WaterHCID 24408BromineHCID 202975304'-chloro-N-methylacetoacetanilide

Product 1

HCID 202975284-bromo-4'-chloro-N-methylacetoacetanilideYield 77.1%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent3×

Procedure

A 500 ml reaction flask fitted with a condenser, drying tube, magnetic stirrer, thermometer and dropping funnel was charged with 38.9 g (0.172 mole) of 4'-chloro-N-methylacetoacetanilide and 350 ml of glacial acetic acid. The dropping funnel contained 27.5 g (0.172 mole) of bromine and a crystal of iodine dissolved in 85 ml of acetic acid. The bromination solution was added dropwise over 45 minutes to the stirred reaction solution while maintaining a pot temperature of about 25°. The solution was allowed to stir at ambient temperature for 48 hours. The acetic acid solution was poured into 800 ml of cold water. The aqueous mixture was twice extracted with 400 ml of ether. The combined ether extracts were washed with water and dried over sodium sulfate. The solvent was removed on the rotary evaporator to give a residual liquid (40.4 g, 77%) which was used in subsequent reactions without further purification. N.M.R. (CDCl3) ∂3.2 (NCH3), 3.7 (O=C CH 2 C=O), 4.0 (O=CCH2Br), 5.0 (CH, enol), 7.2-7.4 (aromatic).

Workup

  1. customA 500 ml reaction flask
  2. customfitted with a condenser
  3. customdrying tube, magnetic stirrer
  4. additionThe bromination solution was added dropwise over 45 minutes to the stirred reaction solution
  5. temperaturewhile maintaining a pot temperature of about 25°
  6. extractionThe aqueous mixture was twice extracted with 400 ml of ether
  7. washThe combined ether extracts were washed with water
  8. dry with materialdried over sodium sulfate
  9. customThe solvent was removed on the rotary evaporator

Sources & evidence

ORD record
ord-79d1066e5a7048448b3759e5657d3fac
Source dataset
uspto-grants-1981_01
Patent number
US04243407

Reaction notes

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