Sulfuric Acid → 5-Bromo-3,4-dihydroquinolin-2(1H)-one

Temperature

0 °C

To a stirred mixture of sodium azide (862 mg, 13.3 mmol) in H2O (1.7 mL) and CHCl3 (6.5 mL) was added conc. H2SO4 (0.23 mL, 4.14 mmol). The reaction mixture was stirred vigorously at 0° C. for 2.5 h. The CHCl3 layer was separated, dried over Na2SO4, and added to a solution of 4-bromo-1-indanone (1.12 g, 5.31 mmol) in CHCl3 (20 mL). To this mixture was added conc. H2SO4 (1.75 mL, 31.5 mmol) dropwise over 10 min. The reaction mixture was heated at 45 C for 1 h then poured into ice-water, neutralized with 20% aqueous NaOH, and extracted with CH2Cl2 (100 mL). The organic extract was dried over Na2SO4, filtered, and concentrated in vacuo. The crude product was purified by silica gel chromatography, eluting with a gradient of CH2Cl2:EtOAc—100:0 to 80:20, to give the title compound. MS: m/z=226 (M+1).

1. customThe CHCl3 layer was separated
2. dry with materialdried over Na2SO4
3. temperatureThe reaction mixture was heated at 45 C for 1 h
4. extractionextracted with CH2Cl2 (100 mL)
5. extractionThe organic extract
6. dry with materialwas dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe crude product was purified by silica gel chromatography
10. washeluting with a gradient of CH2Cl2

ORD record

ord-81a89f9404ff45b48f5d77a4945df4a4

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08143266B2