1,4-Dimethoxybenzene → Benzophenone

A mixture of 2-fluorobenzoyl chloride (15.86 g, 0.1 mole) and 1,4-dimethoxybenzene (13.82 g, 0.1 mole) in 1,2-dichloroethane (200 ml) was cooled in an ice bath and treated cautiously with AlCl3 (13.82 g, 0.103 mole) portionwise. The temperature of the reaction mixture was kept at 0-5° during the addition, and then warmed to room temperature over 4 hrs after completion of addition. The resulting deep red reaction mixture was further refluxed for 1.5 hrs, followed by stirring at room temperature overnight. The reaction was quenched by addition of ice and 6N HCl solution in an ice bath with continued stirring at 0° for an hour. The mixture was then extracted three times with CH2Cl2. The combined organic layers were washed with 50% NaCl solution, dried over anhydrous Na2SO4 and filtered through a silica gel plug, yielding the intermediate benzophenone (24.68 g, 100%) as an orange colored oil which was used for cyclization without further purification. IR (neat): 3070, 2998, 2936, 2736, 1605, 1477, 1445, 1328, 1265, 1226, 1212, 1135, 1038, 960, 870, 792, 758 and 646 cm-1.

1. temperaturewas cooled in an ice bath
2. additionThe temperature of the reaction mixture was kept at 0-5° during the addition
3. additionafter completion of addition
4. customThe resulting deep red reaction mixture
5. temperaturewas further refluxed for 1.5 hrs
6. customThe reaction was quenched by addition of ice and 6N HCl solution in an ice bath
7. stirringwith continued stirring at 0° for an hour
8. extractionThe mixture was then extracted three times with CH2Cl2
9. washThe combined organic layers were washed with 50% NaCl solution
10. dry with materialdried over anhydrous Na2SO4
11. filtrationfiltered through a silica gel plug

ORD record

ord-b3d3b808edae428995262c0bbd7c7a87

Source dataset

uspto-grants-2000_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06162610