Verfahren zur Herstellung von 6-(5'-Nitro-2'-furyl)-azauracil

The invention comprises: (a) 5-(2-furyl) -4-azauracil; (b) 5-(5-nitro -2- furyl) -4- azauracil; and (c) the preparation of compound (b) by heating 2-furoylformic acid semicarbazone with an alkaline ring-closure agent in an inert solvent to form compound (a) and subjecting this to the action of a nitrating mixture including nitric acid. 2-Furoylformic acid semicarbazone is prepared by hydrolysing 2-furoyl cyanide and condensing the resulting crude 2-furoylformic acid with semicarbazide hydrochloride. Pharmaceutical preparations. Compound (b) has antimicrobial properties, and may be administered orally, e.g. in tablets, suspensions, lozenges or capsules.