Hydrochloric Acid → 6-Bromo-4-hydroxyquinolin-2(1H)-one

Temperature

140 °C

The product of Step 2 (14.7 g) was added to polyphosphoric acid (55.3 mL) and mixture was heated to 140° C. for 3 hrs. The reaction mixture was cooled slightly and poured into 3N HCl (168 mL). The pH was adjusted to 4 with 3N NaOH and resulting solid was filtered after cooling the reaction mixture to 10° C. The cake was washed with water and then slurried in 400 mL of 50% isopropanol/water for 18 hours. The solids were filtered, air dried to give a pasty solid which was dried in vacuo at 90° C. for 4 hours, ground in mortar/pestle and re-dried at 90° C. for another 18 hours to give 15 g of the desired product.

1. temperatureThe reaction mixture was cooled slightly
2. customresulting solid
3. filtrationwas filtered
4. temperatureafter cooling the reaction mixture to 10° C
5. washThe cake was washed with water
6. filtrationThe solids were filtered
7. customair dried
8. customto give a pasty solid which
9. customwas dried in vacuo at 90° C. for 4 hours
10. customground in mortar/pestle and re-dried at 90° C. for another 18 hours

ORD record

ord-b784a22d22ba4956a3df129e4e5201d1

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09328138B2