Sodium Hydroxide → 6-phenoxypyridazin-3(2H)-one

Temperature

110 °C

A mixture of 3-chloro-6-phenoxy-pyridazine (1.01 g, 4.89 mmol) and sodium acetate (1.40 g, 17.06 mmol) in glacial acetic acid (50 mL, 0.1M) was heated to 110° C. overnight. After this time the reaction was cooled to 25° C. and was diluted with water (450 mL). The reaction was brought to pH=5-6 by the addition of a 5N aqueous sodium hydroxide solution. The resulting solution was extracted with ethyl acetate (3×100 mL). The combined organics were washed with a saturated aqueous sodium chloride solution (1×100 mL), dried over magnesium sulfate, filtered, rinsed with ethyl acetate and concentrated in vacuo. The resulting oil was azeotroped with methanol four times and dried in vacuo to afford 6-phenoxy-2H-pyridazin-3-one (0.78 g, 86%) as a white solid. 1H-NMR (300 MHz, DMSO-d6) δ ppm 7.00 (d, J=10.0 Hz, 1H), 7.13-7.27 (m, 3H), 7.34-7.46 (m, 3H), 12.29 (br s, 1H).

1. temperatureAfter this time the reaction was cooled to 25° C.
2. extractionThe resulting solution was extracted with ethyl acetate (3×100 mL)
3. washThe combined organics were washed with a saturated aqueous sodium chloride solution (1×100 mL)
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. washrinsed with ethyl acetate
7. concentrationconcentrated in vacuo
8. customThe resulting oil was azeotroped with methanol four times
9. customdried in vacuo

ORD record

ord-5c2870e3e0d64df398a0ba324a40fb27

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08258134B2