反应 #75942

反应方程式

(2R)-3,4-Dihydro-2H-chromene-2-carboxylic acid

benzyltrimethyl-ammonium dichloroiodate

→

crude product

(2R)-6-iodo-3,4-dihydro-2H-chromene-2-carboxylic Acid

溶剂

water

acetic acid

反应条件

后处理

1. 1
   其他The solid was removed by vacuum filtration
2. 2
   洗涤washed with acetic acid (100 mL)
3. 3
   浓缩The filtrate was concentrated in vacuo
4. 4
   其他to obtain a solid which

实验过程

(2R)-3,4-Dihydro-2H-chromene-2-carboxylic acid (WO 99/32476) (26.7 g, 150 mmol), benzyltrimethyl-ammonium dichloroiodate (50.1 g, 144 mmol) and zinc chloride (25.3 g, 186 mmol) were stirred in glacial acetic acid (500 mL) under argon at room temperature for 18 hours. The solid was removed by vacuum filtration and then washed with acetic acid (100 mL). The filtrate was concentrated in vacuo to obtain a solid which was slurried in water (300 mL). The crude product was obtained as a pink solid after vacuum filtration and dried (38.3 g, 84%): 1H NMR (DMSO-d6) δ1.95-2.10 (m, 1H), 2.60 (m, 1H), 2.70-2.80 (m, 1H), 4.79 (dd, J=6.0, 3.9 Hz, 1H), 6.63 (d, J=8.4 Hz, 1H), 7.36 (dd, J=8.1, 1.8 Hz, 1H), 7.38 (d, J=1.8 Hz, 1H). CI-MS m/z 305 (M+H+). The crude was used for next step directly.

来源