Pentylamine → 6-Chloropyridazine-3-carboxylic acid pentylamide

To a flask containing 6-chloropyridazine-3-carboxylic acid (375 mg, 2.37 mmol) in dioxane (5 mL) was added thionyl chloride (420 mg, 0.26 mL, 3.56 mmol). The brown mixture was refluxed for 6 hours under nitrogen with stirring. After cooling to ambient temperature, the solvent was removed by rotary evaporator. The gummy black material was diluted with dioxane (5 mL) and the resulting solution was cooled in an ice-water bath. To the cooled solution was added amyl amine (410 mg, 0.55 mL, 4.74 mmol). The resulting black reaction solution was stirred at ambient temperature for 16 hours under nitrogen. The solvent was removed in vacuo and the residue was dissolved in dichloromethane (25 mL). The solution was washed with water (2×10 mL) and the organic layer was dried over MgSO4, filtered-off the solid and concentrated to afford a gummy material which was purified by column chromatography eluted with dichloromethane to yield 310 mg (57%) of the product as a colourless solid. m.p. 98-101° C. 1H NMR (300 MHz, CDCl3) δ 8.28, 8.05, 7.68, 3.51, 169-1.63, 0.90. MS (ES+) m/z 228 (M+1).

1. temperatureThe brown mixture was refluxed for 6 hours under nitrogen
2. customthe solvent was removed by rotary evaporator
3. additionThe gummy black material was diluted with dioxane (5 mL)
4. temperaturethe resulting solution was cooled in an ice-water bath
5. stirringThe resulting black reaction solution was stirred at ambient temperature for 16 hours under nitrogen
6. customThe solvent was removed in vacuo
7. dissolutionthe residue was dissolved in dichloromethane (25 mL)
8. washThe solution was washed with water (2×10 mL)
9. dry with materialthe organic layer was dried over MgSO4, filtered-off the solid
10. concentrationconcentrated
11. customto afford a gummy material which
12. customwas purified by column chromatography
13. washeluted with dichloromethane

ORD record

ord-d77cb83f2d8048b2a6dbd0c47a890140

Source dataset

uspto-grants-2011_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07964591B2