Reacción #1551

Ecuación de reacción

phosphorous pentoxide

2-phenyl-6-trifluoromethyl-4(3H)-pyrimidinone

dimethoxymethane

phosphorous pentoxide

sodium hydroxide

→

3-methoxymethyl-2-phenyl-6-trifluoromethyl-4(3H)-pyrimidinone

Rendimiento 32.8%

Disolventes

chloroform

methylene chloride

hexane

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroat room temperature
2. 2
   workup.ADDITIONThe reaction mixture was poured
3. 3
   workup.ADDITIONwere added
4. 4
   OtroThe layers were separated
5. 5
   Extracciónthe aqueous layer was extracted twice with methylene chloride
6. 6
   Lavadowashed with brine
7. 7
   Secadodried over MgSO4
8. 8
   Concentraciónconcentrated
9. 9
   Otroto yield 1.1 g crude product, which
10. 10
    Otrowas purified by recrystallization from hexane

Procedimiento

To a solution of 1.5 g (5.9 mmol) of 2-phenyl-6-trifluoromethyl-4(3H)-pyrimidinone, 17.2 g (226.3 mmol) dimethoxymethane, and 35 mL of chloroform was added 2.5 g (17.6 mmol) phosphorous pentoxide, at room temperature. By TLC (25% ethyl acetate in hexane) the reaction was incomplete after 4 h and an additional 3 g (21.1 mmol) phosphorous pentoxide was added. Stirring was continued for 16 h. The reaction mixture was poured onto crushed ice and 1M sodium hydroxide and methylene chloride were added. The layers were separated and the aqueous layer was extracted twice with methylene chloride. The organic extracts were combined and washed with brine, then dried over MgSO4 and concentrated to yield 1.1 g crude product, which was purified by recrystallization from hexane. Thus, 0.55 g (32%) 3-methoxymethyl-2-phenyl-6-trifluoromethyl-4(3H)-pyrimidinone (Compound 6) as a yellow solid was obtained. 1H-NMR (CDCl3) δ 3.55(3H,s); 5.2(2H,d); 6.85(1H,s); 7.65(3H,m); 7.75(2H,m).

Fuente