反応 #2013096

反応方程式

(E)-4-Oxo-but-2-enoic acid ethyl ester

2-nitro benzoic acid

pyrrolidine

3-chloro-2-hydroxy-benzaldehyde

→

5-chloro-3-formyl-2H-chromene-2-carboxylic acid ethyl ester

溶媒

dimethysulfoxide

反応条件

後処理

1. 1
   その他The reaction was quenched by the addition of water
2. 2
   その他The reaction mixture was then partitioned between water and ethyl acetate
3. 3
   洗浄The combined organics were washed with a saturated brine solution
4. 4
   乾燥dried over anhydrous sodium sulfate
5. 5
   ろ過filtered
6. 6
   洗浄rinsed
7. 7
   濃縮concentrated in vacuo
8. 8
   その他The residue obtained
9. 9
   その他was purified on a silica gel Flash column chromatography

実験手順

(E)-4-Oxo-but-2-enoic acid ethyl ester (2.7 mL, 22.99 mmol), 2-nitro benzoic acid (0.648 g, 3.83 mmol), and pyrrolidine (0.31 mL, 3.83 mmol) were added simultaneously to a solution of commercially available 3-chloro-2-hydroxy-benzaldehyde (5.0 g, 19.16 mmol) in dimethysulfoxide (20 mL) at 25° C. and the solution was stirred for 78 hours at 25° C. The reaction was quenched by the addition of water. The reaction mixture was then partitioned between water and ethyl acetate. The combined organics were washed with a saturated brine solution, dried over anhydrous sodium sulfate, filtered, rinsed and concentrated in vacuo. The residue obtained was purified on a silica gel Flash column chromatography using ethyl acetate-hexanes (1:1.2) as eluents, yielded 5-chloro-3-formyl-2H-chromene-2-carboxylic acid ethyl ester as a solid (2.10 g, 50.1%).

出典