반응 #75942

반응 방정식

(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

용매

water

acetic acid

반응 조건

후처리

1. 1
   기타The solid was removed by vacuum filtration
2. 2
   세척washed with acetic acid (100 mL)
3. 3
   농축The filtrate was concentrated in vacuo
4. 4
   기타to obtain a solid which

실험 절차

(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.

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