Substituted 4-hydroxy-3-(1H-tetrazol-5-yl)-quinoline compounds are prepared by reacting substituted 3-cyano-4-hydroxyquinolines with sodium azide to provide useful anti-allergic compounds.
An industrially advantageous process for producing 5,7-dichloro-4-hydroxyquinoline (DCHQ) useful as an intermediate for agrohorticultural bactericides. The process comprises (i) hydrolyzing 3-cyano- or 3-ethoxycarbonyl-5,7-dichloro-4-hydroxyquinoline into 5,7-dichloro-3-carboxy-4-hydroxyquinoline (DCQA) in the presence of hydrochloric, sulfuric or phosphoric acid and (ii) decarboxylating the formed DCQA into DCHQ in the presence of sulfuric or phosphoric acid. In particular, this process comprises continuously conducting the hydrolysis of 5,7-dichloro-3-ethoxycarbonyl-4-hydroxyquinoline and the decarboxylation of the hydrolyzate in the presence of sulfuric acid having a specified concentration. The invention also relates to a process for producing DCQA by hydrolyzing 3-cyano- or 3-ethoxycarbonyl-5,7-dichloro-4-hydroxyquinoline in the presence of hydrochloric, sulfuric or phosphoric acid and a process for producing DCHQ by decarboxylating DCQA in the presence of sulfuric or phosphoric acid.
3-(1H-tetrazol-5-yl)-4(3H)-quinazolinones useful as antiallergic agents are described herein. The compounds are prepared by the reaction of an appropriate 2-amino-N-(1H-tetrazol-5-yl)benzamide with an appropriate ortho ester.
Novel quinolones of formula I ##STR1## and pharmaceutically acceptable acid addition salts thereof in which the dotted line between positions 2 and 3 of the quinolone ring represents an optional bond, R is hydrogen, 1-methyl or 2-lower alkyl; R.sub.1 is lower alkyl; R.sub.2 is hydrogen, halo, lower alkyl, lower alkoxy, trifluoromethyl, cyano, difluoromethoxy, methylsulphinyl, phenylsulphinyl or the group --NR.sub.4 R.sub.5 or the N-oxide thereof wherein R.sub.4 and R.sub.5, which may be the same or different, are lower alkyl or, together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or morpholino radical; and R.sub.3 is hydrogen, fluoro, lower alkyl or lower alkoxy provided that, when R.sub.3 is lower alkoxy, R.sub.2 is other than lower alkoxy have utility as antihypertensive agents. Processes for preparing the quinolones and pharmaceutical compositions containing them are disclosed.
(1H-Tetrazol-5-yl)-2(1H)-quinolones useful as antiallergic agents are described herein. The compounds are prepared by the reaction of sodium azide and ammonium chloride with an appropriate 3-cyano-2(1H)-quinolinone.
A process is provided for preparing pyrazolo-[1,5-c]quinazoline derivatives of the structure ##STR1## wherein X is O or S; R.sup.1 is hydrogen, lower alkyl, hydroxymethyl, phenyl-lower alkyl, phenyl or phenyl substituted with halogen, lower alkyl, lower alkoxy, or trifluoromethyl; R.sup.2 is lower alkoxy, phenyl-lower alkoxy, phenoxy, or phenoxy substituted with lower alkyl or lower alkoxy; and R.sup.3 and R.sup.4 are the same or different and are selected from the group consisting of hydrogen, alkyl of 1 to 4 carbons, alkoxy of 1 to 4 carbons, lower alkanoyloxy of 1 to 4 carbons, nitro, benzyloxy, benzyloxy having a single monolower alkoxy substituent, halogen, hydroxy, and trifluoromethyl, wherein quinolone compounds of the structure ##STR2## which are new intermediates, are reacted with a hydrazine compound to form a 5-(2-aminophenyl)-pyrazole which is then cyclized to the product. In addition, the above product may be reacted with a halogen acid to form the corresponding hydroxymethyl compound.
