Реакция #2320129

Уравнение реакции

paraformaldehyde

paraformaldehyde

N-methylanilinium trifluoroacetate

diethyl ether

α-tetralone

→

2-methylene-3,4-dihydronaphthalen-1-one

Выход 92.4%

Растворители

THF

Условия реакции

Обработка

1. 1
   ТемператураThe solution was heated
2. 2
   Температураat reflux under nitrogen
3. 3
   workup.DISSOLUTIONdissolved
4. 4
   ТемператураAfter cooling
5. 5
   ДругоеThe solvent was separated from the reaction mixture
6. 6
   Промывкаwashed with 500 mL of saturated sodium bicarbonate
7. 7
   workup.ADDITIONAdditional diethyl ether was added to the reaction mixture
8. 8
   Другоеseparated
9. 9
   Экстракцияto back extract the aqueous sodium bicarbonate layer
10. 10
    СушкаThe combined organic layers were dried over magnesium sulfate
11. 11
    Концентрированиеthe solution was then concentrated to a volume of approximately 300 mL
12. 12
    Фильтрацияfiltered through Celite
13. 13
    ДругоеComplete evaporation of the ether

Методика

To a suspension of paraformaldehyde (46.2 g, 1.54 mol) and N-methylanilinium trifluoroacetate (TAMA, 46.2 g, 1.54 mol) in 340 mL of dry THF was added α-tetralone (50 g, 0.342 mol). The solution was heated at reflux under nitrogen with stirring for 4 h, during which time the paraformaldehyde dissolved. After cooling, diethyl ether (700 mL) was added to the reaction mixture. The solvent was separated from the reaction mixture and washed with 500 mL of saturated sodium bicarbonate. Additional diethyl ether was added to the reaction mixture, separated and used to back extract the aqueous sodium bicarbonate layer. The combined organic layers were dried over magnesium sulfate, and the solution was then concentrated to a volume of approximately 300 mL and filtered through Celite. Complete evaporation of the ether yielded 50 g (90%) of crude 2-methylene-3,4-dihydronaphthalen-1-one, which was used immediately for the next reaction to prevent polymerization of the product.

Источник