Hydrochloric Acid → HCID 21291163, compound

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Reaction Steps

16.5 g (0.06 mole) of 5-amino-1-(3,5-dichloropyrid-2-yl)-pyrazole-4-carboxylic acid are slowly heated to 80° C. in a mixture of 150 ml of water, 75 ml of concentrated hydrochloric acid and 20 ml of isopropanol and the reaction mixture is stirred at this temperature until the evolution of gas has ended. The clear solution formed is evaporated to dryness, the residue is suspended in methylene chloride, the suspension is neutralized with aqueous sodium carbonate solution, the organic phase is separated off and the aqueous phase is extracted twice more with methylene chloride. The combined organic phases are dried over sodium sulphate and freed from the solvent in vacuo. 12.7 g (92% of theory) of 5-amino-1-(3,5-dichloropyrid-2-yl)-pyrazole are obtained as an oil. 1H-NMR (CDCl3 /TMS as the internal standard): δ=4.55; 5.55; 7.43; 7.88; and 8.30 ppm.

Provenance & Evidence