Реакция #1551

Уравнение реакции

phosphorous pentoxide

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

dimethoxymethane

phosphorous pentoxide

sodium hydroxide

→

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

Выход 32.8%

Растворители

chloroform

methylene chloride

hexane

ethyl acetate

Условия реакции

Обработка

1. 1
   Другоеat room temperature
2. 2
   workup.ADDITIONThe reaction mixture was poured
3. 3
   workup.ADDITIONwere added
4. 4
   ДругоеThe layers were separated
5. 5
   Экстракцияthe aqueous layer was extracted twice with methylene chloride
6. 6
   Промывкаwashed with brine
7. 7
   Сушкаdried over MgSO4
8. 8
   Концентрированиеconcentrated
9. 9
   Другоеto yield 1.1 g crude product, which
10. 10
    Другоеwas purified by recrystallization from hexane

Методика

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).

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