反応 #2298654

反応方程式

boron tribromide

NaHCO3

1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone

dry ice methanol

NaHCO3

boron tribromide

→

dark brown oil

収率 86.4%

1-[4-(3-chloropropoxy)-3-hydroxyphenyl]ethanone

収率 86.4%

溶媒

methylene chloride

methylene chloride

反応条件

後処理

1. 1
   workup.ADDITIONwas added
2. 2
   その他was kept between −40° C. and −50° C
3. 3
   workup.ADDITIONAfter complete addition
4. 4
   その他to reach −30° C.
5. 5
   その他to go above 0° C.
6. 6
   workup.ADDITIONmost of the addition
7. 7
   その他the organic layer was collected
8. 8
   洗浄The layer was washed with brine
9. 9
   乾燥dried (MgSO4)
10. 10
    濃縮concentrated

実験手順

To a stirred solution of 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone (10.0 g, 0.041 mol) in methylene chloride (120 ml) cooled to −50° C. (dry ice-methanol) was added, dropwise, 1M boron tribromide in methylene chloride (123 ml, 0.12 mol). The temperature was kept between −40° C. and −50° C. After complete addition, the reaction was permitted to reach −30° C., and the TLC checked (ca. 15 min. after final boron tribromide was added). Saturated NaHCO3 was added, dropwise, never allowing the temperature to go above 0° C. during most of the addition. When sufficient NaHCO3 had been added to make the solution basic, the organic layer was collected. The layer was washed with brine, dried (MgSO4), and concentrated to yield 8.1 g of dark brown oil, which solidified on standing. This was chromatographed on a Waters Prep 500 LC (2 silica columns, 2% methanol-methylene chloride as eluent). Upon concentration of the appropriate fractions, 5.8 g of a brown tacky solid were obtained. This was recrystallized from isopropyl ether (with decanting of the yellow isopropyl ether supernatant from the dark brown oily residue) to give initially 2.5 g of a yellow solid. Concentration of the mother liquor gave an additional 0.5 g, m.p.=110°-113° C.

出典