반응 #6330

반응 방정식

Acetic anhydride

(±) N-[(9,9a-dihydro-3-oxo-1H,3H-oxazolo[3,4-a]indol-1-yl)methyl]acetamide

methanesulfonic anhydride

→

title compound

N-[(7-Acetyl-9,9a-dihydro-3-oxo-1H,3H-oxazolo-[3,4-a]indol-1-yl)methyl]acetamide

용매

methylene chloride

methane sulfonic acid

반응 조건

후처리

1. 1
   온도to warm slowly to 20°-25° overnight
2. 2
   workup.ADDITIONThen the mixture is added
3. 3
   추출is extracted with ethyl acetate (4×3 ml)
4. 4
   세척The combined organic layers are washed with saturated aqueous sodium bicarbonate (2 ml), saline (1 ml)
5. 5
   건조dried over anhydrous potassium carbonate
6. 6
   농축concentrated to an oil
7. 7
   추출Extraction of the appropriate band and concentration

실험 절차

Acetic anhydride (53 μl) is slowly added to a mixture of (±) N-[(9,9a-dihydro-3-oxo-1H,3H-oxazolo[3,4-a]indol-1-yl)methyl]acetamide (X diastereomer A, EXAMPLE 18, 21 mg), methanesulfonic anhydride (33 mg) in methylene chloride (0.1 ml) and methane sulfonic acid (0.50 ml) at 0°. The temperature is kept below 15° for 3 hr, then allowed to warm slowly to 20°-25° overnight. Then the mixture is added to crushed ice (0.5 ml). After the ice has melted the mixture is extracted with ethyl acetate (4×3 ml). The combined organic layers are washed with saturated aqueous sodium bicarbonate (2 ml), saline (1 ml), dried over anhydrous potassium carbonate and concentrated to an oil. The oil is place on a silica prepratory plate (14 cm×17.5 cm, 250μ) and developed in methanol/methylene chloride (5/95, 3×). Extraction of the appropriate band and concentration give the title compound.

출처