Potassium Hydroxide → 3-Ethoxycarbonyl-1H-pyrido[2,3-b][1,4]-thiazine

Participants

Reaction Conditions

Reaction Steps

4.8 g of ethyl α-chloro-formylacetate, dissolved in 70 ml of ethanol, are added to a solution of 4 g (0.0317 mole) of 2-mercapto-3-aminopyridine and 1.78 g (0.0317 mole) of potassium hydroxide in 200 ml of ethanol at 25° C. under nitrogen. The mixture is warmed at 50° C. for 1 hour, the ethanol is then stripped off in vacuo and the residue is chromatographed on silica gel with methylene chloride/methanol (95:5) as the mobile phase. Yield: 3.3 g (47% of theory) Melting point: 194°-195° C.

Provenance & Evidence