Hydrochloric Acid → 3-Oxo-2,3-dihydropyridazine-4-carbonitrile

Temperature

40 °C

To a mixture of glyoxal bis(sodium hydrogen sulfite) monohydrate (25.24 g, 88.8 mmol) in water (80 ml) was added slowly a solution of cyanoacetohydrazide (8 g, 80.7 mmol) in ethanol/water 2:1 (120 ml). The mixture was then heated to 40° C. for 30 min. The pH was adjusted to 12-13 by addition of 10 N NaOH and stirring was continued for 3 h at 40° C. and for 1 h at 60° C. The reaction mixture was then allowed to cool to ambient temperature over night. The pH was then adjusted to 1-2 by addition of conc. HCl and the resulting mixture was evaporated. The remaining solid was extracted with CHCl3 in a soxhlet-extractor for two days to obtain the title compound as a light brown solid (2.019 g, 16.67 mmol, 21%). 1H NMR (d6-DMSO): 8.07 (d, J=4 Hz, 1H), 8.12 (d, J=4 Hz, 1H), 13.91 (s br, 1H).

1. temperatureto cool to ambient temperature over night
2. customthe resulting mixture was evaporated
3. extractionThe remaining solid was extracted with CHCl3 in a soxhlet-extractor for two days

ORD record

ord-9c8a16fd0c244c1f805fee19ecca29d3

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07928106B2