FI345974

1438219 Carbocyclic fused quinolones BOEHRINGER MANNHEIM GmbH 2 Dec 1974 [5 Dec 1972] 51982/74 Heading C2C Novel compounds of the Formula I wherein R 1 is hydrogen, alkyl or alkenyl, R 3 is hydrogen or alkyl and n is 1 or 2, in which the alkyl and alkenyl radicals have up to 6 carbon atoms, and pharmaceutically compatible salts of those compounds in which R 3 is hydrogen may be prepared by (1) eliminating HX from a compound of the Formula II wherein X is hydroxy or alkoxy or acyloxy containing up to 4 carbon atoms; (2) for compounds I in which R 1 is alkyl or alkenyl cyclizing and simultaneously eliminating HX1 from a compound of the Formula III wherein R 2 is alkyl or alkenyl containing up to 6 carbon atoms and X1 is hydroxy or acyloxy or alkoxy containing up to 4 carbon atoms; (3). N-alkylating or N-alkenylating a compound I in which R 1 is hydrogen, (4) saponifying or esterifying the carboxylic group and/or (5) forming salts of the compounds I in which R 3 is hydrogen. 1 - Ethyl - 3 - carboxy - 1,4 - dihydro - 7- chloro - cyclopenteno[1,2-h]quinolin - 4 - one is prepared by chlorination of the 7-hydroxy compound. The intermediates III may be prepared by reducing 5-aminotetral-1-one to 5-amino-1-hydroxytetralin which is N-ethylated to yield 5 - ethylamino - 1 - hydroxy - tetralin which on reaction with ethyl ethoxy methylene malonate yields ethyl N - ethyl - N - (1 - hydroxytetralinyl - 5) - aminomethylene malonate which may be used directly as an intermediate III or etherified to ethyl N-ethyl-N-(1 -ethoxytetralinyl-5)- aminomethylene malonate or esterified to ethyl N- ethyl - N - (1 - acetoxytetralinyl - 5) - aminomethylene-malonate. Pharmaceutical compositions of the compounds I with the usual excipients show anti-microbial activity.