Potassium Carbonate → 6-Chloro-2,3-dimethylpyridine

Temperature

100 °C

5,6-dimethyl-2(1H)pyridinone (Example 476, 0.39 g, 3.2 mmol) was suspended in phosphorous oxychloride (5.00 mL, 53.6 mmol) and heated to 100° C. Then, phosphorous pentachloride (4.00 g, 19.2 mmol) was added, and the mixture was heated to 140° C. After 16 h, the mixture was cooled to rt, diluted with CH2Cl2 (5 mL), and slowly poured into a 0° C. solution of potassium hydroxide (5 g) and potassium carbonate (5 g) in water (100 mL). Upon complete addition, the mixture was allowed to warm to rt and stirred for 1 h. The aqueous solution was extracted with CH2Cl2, and the combined organics layers were dried (MgSO4), filtered, and concentrated in vacuo to provide the title compound (0.35 g, 77%) as a brown oil. The material was used in the next step without further purification. 1H NMR (400 MHz, CDCl3) δ 7.36 (d, 1H), 7.07 (d, 1H), 2.49 (s, 3H), 2.27 (s, 3H).

1. temperaturethe mixture was heated to 140° C
2. temperaturethe mixture was cooled to rt
3. additionUpon complete addition
4. temperatureto warm to rt
5. extractionThe aqueous solution was extracted with CH2Cl2
6. dry with materialthe combined organics layers were dried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated in vacuo

ORD record

ord-1dd36045d76f4e8baa8741b221a80be5

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07714004B2