NEW NITROFURL-AMIDINE DERIVATIVES

1366233 3 - [2 - (5 - Nitro - 2 - furyl) - vinyl]- triazolo-[4,3-b]-pyridazines BOEHRINGER MANNHEIM GmbH 3 May 1973 [10 May 1972] 21095/73 Addition to 1309727 Heading C2C Novel compounds (I) in which R 1 and R 2 are hydrogen, C 1-3 alkyl, alkoxyalkyl or alkylthioalkyl and at least one is hydroxy-C 1-3 alkyl, hydroxyphenyl or cyclohexyl or R 1 R 2 N form a 5- or 6-membered ring optionally containing further N, O or S atoms and substituted by hydroxy, alkyl or hydroxyalkyl and their salts are prepared by reacting a compound II in which Y is an alkoxy or alkylthio group (preferably ethoxy) with an amine R 1 R 2 -NH. Compounds I may also be prepared by (i) condensing a compound (III) with 5-nitro-2-furfural or its diacetate, (2) nitration of the compound (IV) or (3) condensation of 3-[2-(5-nitro-2-furyl)- vinyl] - 6 - amino - s - triazolo[4,3 - b]pyridazine with a formamide O = CH-NR11 1 R11 2 in which R11 1 and R11 2 have the same meaning as R 1 and R 2 except that they do not signify hydroxyl containing radicals or with the corresponding acetal or thioamide or with an imino ether R11 1 -N = CH-OR 4 or thioimino ether R11 1 -N = CH-S-R 4 (in which R 4 is alkyl and in the product formed R11 2 is hydrogen) to form compounds I in which R 1 and R 2 do not contain hydroxy groups. NR 1 R 2 represents 4- methyl - 1 - piperazinyl -; p - hydroxyanilino-; N - methyl - N - # - hydroxyethyl - amino; 4- hydroxy - piperidino; N,N - di - # - hydroxyethyl - amino; # - hydroxyethyl - amino or cyclohexylamino. 3 - [2 - (5 - Nitro - 2 - furyl) - vinyl] - 6 - ethoxymethylene - amino - s - triazolo[4,3 - b]pyridazine is prepared by reacting the corresponding 6- amino compound with triethylorthoformate in the presence of acetic anhydride. Compounds I show anti-microbial activity and form with a carrier or diluent a pharmaceutical composition which may be administered orally or parenterally.