Nitroethane → 3-Methyl-5-(4-methylphenyl)isoxazole

HRID 1669800Notes

Reaction equation

HRID 1669800 reaction equation
C1(N=C=O)C=CC=CC=1.[C:10]([C:12]1[CH:17]=[CH:16][C:15]([CH3:18])=[CH:14][CH:13]=1)#[CH:11].[N+:19]([CH2:22][CH3:23])([O-])=[O:20].C(N(CC)CC)C>C1C=CC=CC=1.O>[CH3:23][C:22]1[CH:11]=[C:10]([C:12]2[CH:17]=[CH:16][C:15]([CH3:18])=[CH:14][CH:13]=2)[O:20][N:19]=1

Participants

7

Reactant 4

HCID 6587NitroethaneHCID 7672Phenyl isocyanateHCID 8471TriethylamineHCID 13018p-Ethynyltoluene

Product 1

HCID 103521723-Methyl-5-(4-methylphenyl)isoxazole

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 962WaterSolvent

Procedure

6.23 ml (57.39 mmol) of phenyl isocyanate are added dropwise at room temperature to a solution of 5 g (43.04 mmol) of 1-ethynyl-4-methylbenzene, 1 ml (14.34 mmol) of nitroethane and 0.4 ml (2.87 mmol) of triethylamine in 100 ml of benzene. The reaction mixture is then stirred under reflux for 12 h. After cooling, the suspension is mixed with water (50 ml) and stirred at room temperature for a further 4 h. The precipitate is filtered off with suction and washed with benzene (10 ml). The organic phase of the filtrate is separated off, dried with magnesium sulfate and concentrated. The residue is purified by column chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 6:1). 1.13 g (46% of theory) of the title compound are obtained as a colourless oil.

Workup

  1. temperatureunder reflux for 12 h
  2. temperatureAfter cooling
  3. stirringstirred at room temperature for a further 4 h
  4. filtrationThe precipitate is filtered off with suction
  5. washwashed with benzene (10 ml)
  6. customThe organic phase of the filtrate is separated off
  7. dry with materialdried with magnesium sulfate
  8. concentrationconcentrated
  9. customThe residue is purified by column chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 6:1)

Sources & evidence

ORD record
ord-c18b0c05541743429217e7dd1b28c986
Source dataset
uspto-grants-2011_08
Patent number
US07989633B2

Reaction notes

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