Reacción #2346935

Ecuación de reacción

3,4-dihydroxyphenylacetic acid

p-toluenesulfonic acid

acetone

→

intended compound

2,2-Dimethyl-5-(2-hydroxyethyl)-1,3-benzodioxole

Disolventes

benzene

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaunder reflux for 18 h
2. 2
   ConcentraciónThe reaction mixture was concentrated
3. 3
   workup.DISSOLUTIONthe obtained dark brown oil was dissolved in 20 ml of tetrahydrofuran
4. 4
   workup.ADDITIONThe solution was added to a suspension of 0.8 g of lithium aluminum hydride in 30 ml of tetrahydrofuran
5. 5
   Temperaturaunder cooling with ice
6. 6
   Temperaturacooled with ice/water
7. 7
   workup.ADDITION0.8 ml of water, then 0.8 ml of a 15% aqueous sodium hydroxide solution and finally 2.4 ml of water were added
8. 8
   Filtraciónan insoluble substance was filtered off
9. 9
   ConcentraciónThe filtrate was concentrated
10. 10
    workup.ADDITIONtreated

Procedimiento

1.7 g of 3,4-dihydroxyphenylacetic acid, a catalytic amount of p-toluenesulfonic acid, 10 ml of acetone and 10 ml of benzene were heated under reflux for 18 h. The reflux solution was dehydrated with Molecular Sieve 4A. The reaction mixture was concentrated and the obtained dark brown oil was dissolved in 20 ml of tetrahydrofuran. The solution was added to a suspension of 0.8 g of lithium aluminum hydride in 30 ml of tetrahydrofuran under cooling with ice. The mixture was stirred at room temperature for 1 h and then cooled with ice/water. 0.8 ml of water, then 0.8 ml of a 15% aqueous sodium hydroxide solution and finally 2.4 ml of water were added thereto and an insoluble substance was filtered off. The filtrate was concentrated and treated according to silica gel column chromatography (ethyl acetate/n-hexane=1:1) to obtain 1.1 g of the intended compound in the form of a colorless oil.

Fuente