Ammonia → Pyridazine-3-carboxamide

Temperatur

-30 °C

To a cooled solution of pyridazine-3-carboxylic acid (1.0 g, 8.06 mmol) in tetrahydrofuran (40 mL) in a dry-ice bath was added 4-methyl-morpholine (0.9 g, 8.87 mmol) and isopropyl chloroformate (1.1 g, 8.87 mmol) slowly. The reaction was stirred at −30° C. for 6 hours, then an aqueous solution of ammonia (8 mL, 10% W/W) was added. The resulting mixture was stirred at room temperature overnight, washed with a saturated aqueous solution of potassium bisulfate (50 mL). The aqueous layer was extracted with ethyl acetate (30 mL×3). The combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo to afford 202.5 mg of the desired product (yield was 20.4%). MS obsd. (ESI+) [(M+H)+] 124, 1H NMR (400 MHz, CD3OD) δ ppm 9.45-9.35 (t, J=1.6 Hz, 1 H), 8.58 (s, 1 H), 8.23-8.15 (d, J=7.6 Hz, 1 H), 7.98-7.88 (m, 2 H).

1. stirringThe resulting mixture was stirred at room temperature overnight
2. washwashed with a saturated aqueous solution of potassium bisulfate (50 mL)
3. extractionThe aqueous layer was extracted with ethyl acetate (30 mL×3)
4. dry with materialThe combined organic layers were dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo

ORD-Eintrag

ord-2c2d9e192f20410fb389d7ec9596fc79

Quelldatensatz

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08871756B2