반응 #2027395

반응 방정식

3-bromomethyl-2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-5-ol

phenol

N-methylpiperazine

→

2,2,4,6,7-pentamethyl-3-[(4-methylpiperazino)-methyl]-2,3-dihydro-1-benzofuran-5-ol

수율 63.0%

용매

acetonitrile

반응 조건

후처리

1. 1
   온도at reflux temperature for 60 hrs
2. 2
   기타The precipitate that formed
3. 3
   기타is collected
4. 4
   세척washed with acetonitrile
5. 5
   추출The product is extracted twice with ethyl acetate
6. 6
   세척the extract is washed with water and brine
7. 7
   건조dried (sodium sulfate)
8. 8
   기타evaporated
9. 9
   workup.DISSOLUTIONThe resulting solid is dissolved in ethanol (150 mL)
10. 10
    기타2N hydrochloric acid (150 mL), and evaporated
11. 11
    기타The resulting solid is recrystallized in ethanol/ethyl acetate
12. 12
    기타to give
13. 13
    기타after drying at 60° C. under 13 Pa and equilibration in a moist atmosphere for 24 hrs

실험 절차

A solution of 3-bromomethyl-2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-5-ol (81 g, 270 mmol), phenol (26.75 g, 284 mmol) and N-methylpiperazine (28.47 g, 284 mmol) in acetonitrile (300 ml) is stirred at reflux temperature for 60 hrs. The precipitate that formed is collected, washed with acetonitrile and slurtied in 10% sodium bicarbonate solution. The product is extracted twice with ethyl acetate, and the extract is washed with water and brine, dried (sodium sulfate) and evaporated. The resulting solid is dissolved in ethanol (150 mL) and 2N hydrochloric acid (150 mL), and evaporated to near dryness. The resulting solid is recrystallized in ethanol/ethyl acetate to give after drying at 60° C. under 13 Pa and equilibration in a moist atmosphere for 24 hrs, 48.60 g (44%) of 2,2,4,6,7-pentamethyl-3-[(4-methylpiperazino)-methyl]-2,3-dihydro-1-benzofuran-5-ol dihydrochloride hydrate, mp=172°-3° C.(dec.). A second crop of 19.63 g of 2,2,4,6,7-pentamethyl-3-[(4-methylpiperazino)-methyl]-2,3-dihydro-1-benzofuran-5-ol (total yield 63%) could be obtained from the filtrate after purification of the free base by column chromatography on silica gel eluting with dichloromethane/methanol 9:1.

출처