反应 #9878

反应方程式

HCl

benzylmalonic acid

paraformaldehyde

diethylamine

→

compound 17

收率 90.0%

2-methylene-3-phenylpropanoic acid

收率 90.0%

溶剂

water

ethyl acetate

反应条件

后处理

1. 1
   其他the reaction temperature below 20° C. (see FIG. 6)
2. 2
   温度The reaction was then warmed
3. 3
   温度to reflux for 90 min
4. 4
   温度cooled again on ice
5. 5
   其他the reaction temperature below 10° C
6. 6
   其他The phases were then separated
7. 7
   洗涤The organic layer was washed with brine (100 mL)
8. 8
   干燥dried over sodium sulfate
9. 9
   过滤filtered
10. 10
    浓缩the filtrate concentrated under vacuum

实验过程

A solution of benzylmalonic acid (20.0 g, 0.103 mol, 1 eq) and paraformaldehyde (4.94 g, 0.164 mol, 1.6 eq) in ethyl acetate (150 mL) was cooled (0° C.) and treated with diethylamine (10.65 mL, 0.103 mol, 1 eq) drop wise, keeping the reaction temperature below 20° C. (see FIG. 6). The reaction was then warmed to reflux for 90 min and cooled again on ice. The homogeneous solution was treated with water (20 mL) and concentrated aqueous HCl (12N) (9.0 mL, 0.108 mol) drop wise, keeping the reaction temperature below 10° C. The phases were then separated. The organic layer was washed with brine (100 mL), dried over sodium sulfate, filtered, and the filtrate concentrated under vacuum giving compound 17 as a white solid (15 g, 90%). Rf 0.46 (hexane/EtOAc=7:3). 1H NMR (300 MHz, CDCl3) δ 7.28 (m, 5H), 6.42 (s, 1H), 5.62 (s, 1H), 3.67 (s, 2H). [M−H]− 161.0: tR=2.53 min; purity: 99%.

来源