Hydrochloric Acid → HCID 19380176, compound

Participants

Reaction Steps

4 g. 2-Methylthio-3-nitropyrazolo[1,5-a]pyridine (see Heterocycles, 6, 379/1977; Chem. Pharm. Bull., 25, 1528/1977) are dissolved in 200 ml. concentrated hydrochloric acid and mixed with 20 g. stannous chloride dihydrate. After 1 hour, there are again added 15 g. stannous chloride dihydrate, 15 ml. concentrated hydrochloric acid and 200 ml. water. After a further reaction period of 1 hour, the reaction mixture is poured on to ice, the yellow solution is rendered alkaline and extracted with ethyl acetate. The organic phase is dried and evaporated, the residue is dissolved in a little ethanol and mixed with ethereal hydrochloric acid in order to form the hydrochloride. There are obtained 3.9 g. (95% of theory) of the title compound; m.p. 226° C.

Provenance & Evidence