تفاعل #75942

معادلة التفاعل

(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

المذيبات

water

acetic acid

ظروف التفاعل

المعالجة

1. 1
   أخرىThe solid was removed by vacuum filtration
2. 2
   غسيلwashed with acetic acid (100 mL)
3. 3
   تركيزThe filtrate was concentrated in vacuo
4. 4
   أخرىto obtain a solid which

الإجراء التجريبي

(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.

المصدر