Réaction #1551

Équation de réaction

phosphorous pentoxide

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

dimethoxymethane

phosphorous pentoxide

sodium hydroxide

→

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

Rendement 32.8%

Solvants

chloroform

methylene chloride

hexane

ethyl acetate

Conditions de réaction

Traitement

1. 1
   Autreat room temperature
2. 2
   workup.ADDITIONThe reaction mixture was poured
3. 3
   workup.ADDITIONwere added
4. 4
   AutreThe layers were separated
5. 5
   Extractionthe aqueous layer was extracted twice with methylene chloride
6. 6
   Lavagewashed with brine
7. 7
   Séchagedried over MgSO4
8. 8
   Concentrationconcentrated
9. 9
   Autreto yield 1.1 g crude product, which
10. 10
    Autrewas purified by recrystallization from hexane

Mode opératoire

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).

Source