N-bromobutanimide → Methyl 4-MethylcinnaMate

HRID 1105630Notes

Reaction equation

HRID 1105630 reaction equation
[C:1](/[CH:5]=[CH:6]/[C:7]1[CH:12]=[CH:11][C:10]([CH3:13])=[CH:9][CH:8]=1)([O:3][CH3:4])=[O:2].[Br:14]N1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl>[C:1](/[CH:5]=[CH:6]/[C:7]1[CH:8]=[CH:9][C:10]([CH2:13][Br:14])=[CH:11][CH:12]=1)([O:3][CH3:4])=[O:2]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 5314312Methyl (2E)-3-(4-methylphenyl)-2-propenoate

Product 1

HCID 11658908Methyl 4-MethylcinnaMateYield 99.3%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

A mixture of 4-{(E)-2-carbomethoxyethenyl}toluene (17.6 g), N-bromosuccinimide (17.8 g) and a trace of dibenzoxylperoxide was refluxed in carbon tetrachloride under illumination until the brown-red colour disappeared. Filtration and evaporation of the solvent gave 4-{(E)-2-carbomethoxyethenyl}benzyl bromide (25.3 g). This was dissolved in dry tetrahydrofuran, heated with the sodium salt of ethyl acetoacetate (15.2 g) and a trace of potassium iodide and refluxed for 1.5 days. The solvent was removed the residue partitioned between ether and water and the ether layer dried. Removal of the solvent gave an oil (26.6 g). This was stirred with sodium hydroxide (10 g) in water (400 ml) for 2 days. The solution was extracted with ether, the aqueous layer made acidic with hydrochloric acid and this was heated on a steam bath for 1 h. The solution was extracted with chloroform and the organic layer dried (MgSO4). Removal of the solvent gave the acid of the title compound (11.0 g). This was esterified with methanol-sulphuric acid to give the title compound. τ(CDCl3) 7.9 (3H, s), 7.0-7.5 (4H, m), 6.25 (3H, s), 3.65 (1H, d, J= 16 Hz), 2.85 (2H, d, J=8 Hz), 2.6 (2H, d, J=8 Hz), 2.4 (1H, d, J=16 Hz).

Workup

  1. filtrationFiltration and evaporation of the solvent

Sources & evidence

ORD record
ord-0ba4495ca4184f1db81cd711e292195b
Source dataset
uspto-grants-1982_01
Patent number
US04309443

Reaction notes

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