Phosphorus oxychloride → Methyl 3-[2-chloro-4-(4-chlorophenyl)-5-oxazolyl]propionate

HRID 2300672Notes

Reaction equation

[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[NH:9][C:10](=O)[O:11][C:12]=2[CH2:13][CH2:14][C:15]([O:17][CH3:18])=[O:16])=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:22])=O>N1C=CC=CC=1>[Cl:22][C:10]1[O:11][C:12]([CH2:13][CH2:14][C:15]([O:17][CH3:18])=[O:16])=[C:8]([C:5]2[CH:6]=[CH:7][C:2]([Cl:1])=[CH:3][CH:4]=2)[N:9]=1

Participants

Conditions

Temperature: 150 °C

Procedure

A mixture of methyl 3-[4-(4-chlorophenyl)-2-oxo-4-oxazoline-5-yl]propionate (11.3 g), phosphorus oxychloride (18.6 g) and pyridine (3.2 ml) was stirred at 120 to 180° C. for 80 minutes. The reaction mixture was concentrated, and ice water was added thereto and then stirred at room temperature for 30 minutes. Then, this was extracted with ethyl acetate. The ethyl acetate layer was washed with water, and dried (MgSO4). The solvent was evaporated, and the crystals thus precipitated were collected by filtration. These were recrystallized from isopropyl ether to give colorless needles of methyl 2-chloro-4-(4-chlorophenyl)-5-oxazolepropionate (8.56 g, 71%). m.p. 71-72° C.

Workup

concentrationThe reaction mixture was concentrated
additionice water was added
stirringstirred at room temperature for 30 minutes
extractionThen, this was extracted with ethyl acetate
washThe ethyl acetate layer was washed with water
dry with materialdried (MgSO4)
customThe solvent was evaporated
customthe crystals thus precipitated
filtrationwere collected by filtration
customThese were recrystallized from isopropyl ether

Sources & evidence

ORD record: ord-820cc0763dbf488587f7ad1c9ba7c3a5
Source dataset: uspto-grants-2002_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06498179B1

Reaction notes

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