Phosphorus pentachloride → 2-(dimethylamino)-4-(trifluoromethyl)-6H-1,3-oxazin-6-one

HRID 277352

Reaction equation

HRID 277352 reaction equation
[CH3:1][N:2]([CH3:17])[C:3]([NH:5]/[C:6](/[C:13]([F:16])([F:15])[F:14])=[CH:7]\[C:8]([O:10]CC)=[O:9])=O.P(Cl)(Cl)(Cl)(Cl)Cl>O=P(Cl)(Cl)Cl>[CH3:17][N:2]([CH3:1])[C:3]1[O:10][C:8](=[O:9])[CH:7]=[C:6]([C:13]([F:14])([F:15])[F:16])[N:5]=1

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 11334267Ethyl (Z)-3-(dimethylcarbamoylamino)-4,4,4-trifluoro-but-2-enoate

Product 1

HCID 37238622-(dimethylamino)-4-(trifluoromethyl)-6H-1,3-oxazin-6-oneYield 93.8%

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

A solution of ethyl 3-[N-(N,N-dimethylcarbamoyl)-amino]-4,4,4-trifluorocrotonate (5.08 g, 0.02 mol) in phosphorus oxytrichloride (3 mL) is treated with phosphorus pentachloride (4.16 g, 0.02 mol) in three portions at 15 minute intervals, stirred for 30 minutes, and quenched with ice and water. The resultant aqueous mixture is extracted with ethyl acetate. The organic layer is washed sequentially with saturated sodium bicarbonate and water, and evaporated to give the title product as a white solid (3.9 g, 93.8% yield) which is identical by 1H and 19F NMR to a sample prepared by the literature procedure (Bull. Soc. Chem. Belg. 101, 313, 1992). The title product is further purified by crystallization from heptane (74.5% crystallized yield).

Workup

  1. customquenched with ice and water
  2. extractionThe resultant aqueous mixture is extracted with ethyl acetate
  3. washThe organic layer is washed sequentially with saturated sodium bicarbonate and water
  4. customevaporated

Sources & evidence

ORD record
ord-a8fc7eb9a01f44aba5b5a4ad22ee62cb
Source dataset
uspto-grants-2002_03
Patent number
US06355796B1

Linked notes

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