Thionyl Chloride → 8-Acetyl-3-methoxy-benzo[c]chromen-6-one
Reaction equation
[C:1]([C:4]1[CH:5]=[C:6]([C:20]([OH:22])=[O:21])[C:7]([C:10]2[CH:15]=[CH:14][C:13]([O:16][CH3:17])=[CH:12][C:11]=2OC)=[CH:8][CH:9]=1)(=[O:3])[CH3:2].O=S(Cl)Cl.[Al+3].[Cl-].[Cl-].[Cl-]>ClCCCl>[C:1]([C:4]1[CH:9]=[CH:8][C:7]2[C:10]3[C:11](=[CH:12][C:13]([O:16][CH3:17])=[CH:14][CH:15]=3)[O:22][C:20](=[O:21])[C:6]=2[CH:5]=1)(=[O:3])[CH3:2]Participants
5
Conditions
- Temperature
- 0 °C
Procedure
The compound from Step C was mixed with 1,2-dichloroethane (60 ml) and SOCl2 (1.7 ml, 23 mmol) was added. The mixture was refluxed for 90 min and then cooled to 0° C. AlCl3 (2.3 g, 17.3 mmol) was added and the reaction stirred at room temperature overnight. The solvent was removed and the crude product chromatographed on silica gel with hexane/ethyl acetate (1:1) to yield 5.1 g (90%) of the title compound. 1H-NMR (400 MHz, CDCl3) δH 2.74 (3H, s, COCH3), 3.94 (3H, s, OCH3), 6.92 (1H, s, ArH), 6.99 (1H, d, ArH), 8.02 (1H, d, ArH), 8.11 (1H, d, ArH), 8.41 (1H, d, ArH), 8.91 (1H, s, ArH).
Workup
- additionwas added
- temperatureThe mixture was refluxed for 90 min
- customThe solvent was removed
- customthe crude product chromatographed on silica gel with hexane/ethyl acetate (1:1)
Sources & evidence
- ORD record
- ord-f313c1aa751d4e14a2f724ef770a17fb
- Source dataset
- uspto-grants-2003_07
- Patent number
- US06599921B2
Reaction notes
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