Hydrochloric Acid → HCID 12274202, compound

Participants

Reaction Steps

A mixture of 3.7 g of zinc, 0.22 g of mercuric chloride, 0.22 ml of concentrated hydrochloric acid and 3.7 ml of water is stirred for 5 minutes, and the aqueous solution is removed by decantation. To the zinc amalgam thus obtained are added 6 ml of dioxane and 6 ml of concentrated hydrochloric acid. 1.5 g of 2-(5-oxo-5H-[1]benzothiopyrano[2,3-b]pyridin-7-yl)propionic acid is added to the mixture with stirring at 50°-60°C over a period of about 15 minutes. The whole mixture is stirred at 60°C for 1 hour. The excess zinc is removed by filtration, and the filtrate is evaporated under reduced pressure. The residue is dissolved in water, and the solution is adjusted to pH 2-3 by addition of 10% sodium hydroxide. The resulting crystalline precipitate is filtered off, and recrystallized from aqueous dioxane to give 0.8 g of 2-(5H-[1]benzothiopyrano[2,3-b]pyridin-7-yl)propionic acid as pale yellowish white crystals melting at 203°-204°C.

Provenance & Evidence