Aminomethylation of 6hydroxy-8-nitroquinoline

ABSTRACT

Quinoline having aminomethyl-or nitro-group in their nucleus exhibit marked pharmacological properties. Such compounds possess distinguished antimalarial[1], amoebicidal [2-4], acaricidal [5] and antispasmodic [6] activities. It seems, therefore of interest to synthesize some new quinolinol derivatives bearing both the two aforementioned groups for pharmacological evaluation. Although 6-hydroxy-8-nitroquinoline [1] retards several reactions typical of phenols [c.f. experimental], it undergoes aminomethylation under the Mannich reaction conditions [1] to give the Mannich base derivatives IIa-e. Thus, when nitroquinolinol [I] was allowed to condense with paraformaldehyde and a secondary amine in dioxan, the corresponding 5-aminomethyl derivatives IIa-e were isolated in good yield as solid free bases. The amines used were dimethylamine, diethylamine, diethanolamine, piperidine and morpholine. The same products IIa-e were also isolated when the reaction was carried using two mole-equivalents of both the secondary amines and paraformaldehyde mole of the nitroquinolinol I. Adducts IIa-e gave the correct analytical values. They respond positively to the ferric chloride colour reaction and soluble in cold 10 percent sodium hydroxide solution