反应 #2348157

反应方程式

sodium bicarbonate

6-bromo-4,4-dimethyl-1,4-dihydro-benzo[d][1,3]oxazin-2-one

1-tert-butoxycarbonylpyrrole-2-boronic acid

potassium carbonate

→

2-(4,4-dimethyl-2-oxo-1,4-dihydro-2H-benzo[d][1,3]oxazin-6-yl)-pyrrole-1carboxylic acid tert-butyl ester

收率 58.4%

溶剂

toluene

ethanol

water

反应条件

后处理

1. 1
   温度to cool
2. 2
   萃取extracted with ethyl acetate (3×200 mL)
3. 3
   洗涤washed with water (200 mL) and brine (100 mL)
4. 4
   干燥dried over magnesium sulfate
5. 5
   过滤The solution was filtered
6. 6
   浓缩concentrated in vacuo
7. 7
   其他the residue was purified by flash column chromatography on silica gel (30% ethyl acetate/hexane)

实验过程

A solution of 6-bromo-4,4-dimethyl-1,4-dihydro-benzo[d][1,3]oxazin-2-one (5.0 g, 20 mmol) and tetrakis(triphenylphosphine)palladium(0) (580 mg, 0.5 mmol) in toluene (200 mL) was stirred under a flow of nitrogen for 25 min. To the solution was added sequentially 1-tert-butoxycarbonylpyrrole-2-boronic acid (8.24 g, 39 mmol) in absolute ethanol (50 mL) and potassium carbonate (5.39 g, 39 mmol) in water (50 mL). The mixture was heated to 80° C. for 16 hours and allowed to cool. The reaction mixture was poured into aqueous saturated sodium bicarbonate solution (200 mL) and extracted with ethyl acetate (3×200 mL). The organic layers were combined, washed with water (200 mL) and brine (100 mL) and dried over magnesium sulfate. The solution was filtered, concentrated in vacuo, and the residue was purified by flash column chromatography on silica gel (30% ethyl acetate/hexane) to give 2-(4,4-dimethyl-2-oxo-1,4-dihydro-2H-benzo[d][1,3]oxazin-6-yl)-pyrrole-1carboxylic acid tert-butyl ester (4.0 g, 58%) as a tan solid, mp 172-173° C.

来源