Methanol → 1-[2-(3,4-Dichloro-phenyl)-4-methyl-pent-2-enoyl]-3-methyl-urea

HRID 276235Notes

Reaction equation

HRID 276235 reaction equation
CO[C:3](=[O:17])[C:4]([C:9]1[CH:14]=[CH:13][C:12]([Cl:15])=[C:11]([Cl:16])[CH:10]=1)=[CH:5][CH:6]([CH3:8])[CH3:7].[CH3:18][NH:19][C:20]([NH2:22])=[O:21].C[O-].[Mg+2].C[O-].CO>>[Cl:16][C:11]1[CH:10]=[C:9]([C:4](=[CH:5][CH:6]([CH3:7])[CH3:8])[C:3]([NH:22][C:20]([NH:19][CH3:18])=[O:21])=[O:17])[CH:14]=[CH:13][C:12]=1[Cl:15]

Participants

5

Reactant 4

HCID 887MethanolHCID 11719MethylureaHCID 164537Methanol, magnesium salt (2:1)HCID 674835012-(3,4-Dichloro-phenyl)-4-methyl-pent-2-enoic acid methyl ester

Product 1

HCID 674831831-[2-(3,4-Dichloro-phenyl)-4-methyl-pent-2-enoyl]-3-methyl-ureaYield 32.4%

Conditions

Temperature
25 °C

Procedure

The isomeric mixture of 2-(3,4-dichloro-phenyl)-4-methyl-pent-2-enoic acid methyl ester [749.0 mg, 2.74 mmol, (E):(Z)=3.5:1] and methyl urea (812.6 mg, 10.97 mmol) were treated with a solution of magnesium methoxide in methanol (7.4 wt %, 16 mL, 10.97 mmol). The resulting reaction mixture was heated under reflux for 15 h. The reaction mixture was allowed to cool to 25° C. and then filtered through celite. The celite was thoroughly washed with ethyl acetate. The filtrate was concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 9/1 hexanes/ethyl acetate) afforded impure 1-[2-(3,4-dichloro-phenyl)-4-methyl-pent-2-enoyl]-3-methyl-urea (280.2 mg) as a white solid. A second flash chromatography (Merck Silica gel 60, 230-400 mesh, 3/2 hexanes/diethyl ether) again afforded impure 1-[2-(3,4-dichloro-phenyl)-4-methyl-pent-2-enoyl]-3-methyl-urea (114.6 mg) as a white solid. Recrystallization from hexanes/ethyl acetate afford pure (E)-1-[2-(3,4-dichloro-phenyl)-4-methyl-pent-2-enoyl]-3-methyl-urea (24.7 mg, 3%) as a white solid: mp 177-178° C.; FAB-HRMS m/e calcd for C14H16Cl2N2O2 (M+H)+315.0667, found 315.0652.

Workup

  1. customThe resulting reaction mixture
  2. temperaturewas heated
  3. temperatureunder reflux for 15 h
  4. filtrationfiltered through celite
  5. washThe celite was thoroughly washed with ethyl acetate
  6. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-e7b9a1c053cf401bb382789ac1fe7463
Source dataset
uspto-grants-2002_03
Patent number
US06353111B1

Reaction notes

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