Phosphorus oxychloride → Ethyl(4-methyl-2-phenyl-1,3-oxazol-5-yl)acetate

HRID 46025Notes

Reaction equation

[C:1]([NH:9][CH:10]([CH3:19])[C:11](=[O:18])[CH2:12][C:13]([O:15][CH2:16][CH3:17])=[O:14])(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O=P(Cl)(Cl)Cl.C([O-])(O)=O.[Na+]>CN(C=O)C>[CH2:16]([O:15][C:13](=[O:14])[CH2:12][C:11]1[O:18][C:1]([C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)=[N:9][C:10]=1[CH3:19])[CH3:17]

Participants

Conditions

Temperature: 90 °C

Procedure

To a crude mixture of ethyl 4-(benzoylamino)-3-oxopentanoate (0.6 g, 2.28 mmol) in DMF (4 mL) at rt, was added POCl3 (1.04 g, 6.84 mmol). The resulting solution was heated at 90° C. for 1 hour, then cooled down to rt, and poured into ice for 30 minutes. The aqueous solution was carefully added to a saturated aqueous solution of NaHCO3. Phases were separated with EtOAc and the combined organic extracts were dried over MgSO4 and solvent removed under reduced pressure. The crude material was purified on Biotage small column using a solvent gradient of 0 to 50% EtOAc/Hexane. This gave ethyl(4-methyl-2-phenyl-1,3-oxazol-5-yl)acetate (0.269 g 48% yield) as yellowish oil. ES-MS m/z 246.2 ((MH)+); HPLC RT (min.) 2.77; 1H NMR (CDCl3) δ 8.01-7.98 (m, 2H), 7.45-7.41 (m, 3H), 4.20 (q, 2H), 3.71 (s, 2H), 2.21 (s, 3H), 1.28 (t, 3H).

Workup

temperaturecooled down to rt
additionpoured into ice for 30 minutes
customPhases were separated with EtOAc
dry with materialthe combined organic extracts were dried over MgSO4 and solvent
customremoved under reduced pressure
customThe crude material was purified on Biotage small column

Sources & evidence

ORD record: ord-e451706f1afb4ab0be6e93c4b0b78fb5
Source dataset: uspto-grants-2013_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08541618B2

Reaction notes

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