Sodium hydride → HCID 22222488, compound

In 10 ml of tetrahydrofuran was suspended 230 mg of 60% sodium hydride. The mixture (1 g) of 2,3-dimethyl-4-hydroxy-6,7-difluoroquinoline with 2,3-dimethyl-4-hydroxy-5,6-difluoroquinoline (starting material 1) prepared as described in Example 4 was suspended in 20 ml of tetrahydrofuran, and this suspension of starting material 1 was added dropwise to the above suspension under ice cooling. The reaction mixture was stirred for one hr. Acetyl chloride (starting material 2) (450 mg) was added thereto, and the mixture was then stirred at room temperature for 15 hr. The reaction solution was poured into water, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with a saturated aqueous sodium hydrogencarbonate solution and saturated brine and was then dried over anhydrous sodium sulfate. The solvent was then removed by evaporation under the reduced pressure. The crude product thus obtained was purified on Wako Gel C-200 (200 ml; elution solvent=n-hexane-ethyl acetate (10:1)) to give 262.5 mg of 2,3-dimethyl-4-acetyloxy-6,7-difluoroquinoline (compound 17). 1H-NMR data are shown in Table 3.

1. additionwas added dropwise to the above suspension under ice cooling
2. stirringthe mixture was then stirred at room temperature for 15 hr
3. extractionthe mixture was extracted with ethyl acetate
4. washThe ethyl acetate layer was washed with a saturated aqueous sodium hydrogencarbonate solution and saturated brine
5. dry with materialwas then dried over anhydrous sodium sulfate
6. customThe solvent was then removed by evaporation under the reduced pressure
7. customThe crude product thus obtained
8. customwas purified on Wako Gel
9. wash(200 ml; elution solvent=n-hexane-ethyl acetate (10:1))

ORD record

ord-25c261c93f114a3c8fa016b8b4c43cf5

Source dataset

uspto-grants-2006_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07022855B2