Methyl acetoacetate → Methyl 5-methyl-3-phenyl-1,2-oxazole-4-carboxylate

HRID 1375632

Reaction equation

HRID 1375632 reaction equation
[C:1](=[N:9][OH:10])(Cl)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:11]([O:17][CH3:18])(=[O:16])[CH2:12][C:13]([CH3:15])=O.C(N(CC)CC)C.C(OCC)(=O)C>C(O)C.C(Cl)Cl>[CH3:18][O:17][C:11]([C:12]1[C:1]([C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)=[N:9][O:10][C:13]=1[CH3:15])=[O:16]

Participants

7

Reactant 4

HCID 7757Methyl acetoacetateHCID 8471TriethylamineHCID 8857Ethyl AcetateHCID 2756315N-hydroxybenzenecarboximidoyl chloride

Product 1

HCID 727920Methyl 5-methyl-3-phenyl-1,2-oxazole-4-carboxylateYield 39%

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 6344DichloromethaneSolvent

Procedure

An ethanol solution of freshly prepared benzoyl chloride oxime (14.0 g, 90 mmol) (100 mL) was added dropwise, at 5° C. to methyl acetoacetate (11.18 g, 96 mmol) and triethyl amine (13 mL, 103 mmol) in ethanol (50 ml) After stirring for 12 hr at ambient temperature, the solution was diluted with CH2Cl2, washed with 1N HCl. saturated NaHCO3, brine, dried over MgSO4 and evaporated to give amber oil. Flash chromatography (silica) with 10% ethyl acetate in hexanes afforded the title compound (7.56 g, 39% yield) as a white solid: MS m/z MH+218 (100); 1H NMR (CDCl3) δ 2.78 (s, 3H), 3.81 (s, 3H), 7.45–7.55 (m, 3H), 7.65–7.69 (m, 2H).

Workup

  1. washwashed with 1N HCl
  2. dry with materialsaturated NaHCO3, brine, dried over MgSO4
  3. customevaporated
  4. customto give amber oil

Sources & evidence

ORD record
ord-85ee4dd0ad78463d8ae1db24a55b2f05
Source dataset
uspto-grants-2007_01
Patent number
US07169798B2

Linked notes

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