4,7-Dichloroquinoline is a two-ring heterocyclic compound used as a chemical intermediate to aminoquinoline antimalarial drugs including amodiaquine, chloroquine and hydroxychloroquine.

[2] However, its synthesis was not investigated in detail until chloroquine was developed as an antimalarial drug.

[3]: 130–132  A route to the intermediate starting from 3-chloroaniline was developed by chemists at Winthrop Chemical Co.[4] The substituted aniline is condensed with the diethyl ester of oxaloacetic acid under mildly acidic conditions, forming an imine, which is cyclised to form the pyridine ring by heating in mineral oil.

[4] The availability of 4,7-dichloroquinoline allowed alternative structural analogs of the 4-aminoquinoline type to be investigated, leading to the discovery of hydroxychloroquine in 1949.

A typical reaction with a specific primary amine gives chloroquine in high yield:[6][7] Apart from its use in the manufacture of antimalarials already described, 4,7-dichloroquinoline is of continuing interest as an intermediate to new drug candidates.