4,10-Dihydro-4,10-dioxo-1H-1-benzopyrano[3,2-b]pyridine-2-carboxylic acids and esters

Abstract

There is disclosed 4,10-dihydro-4,10-dioxo-1H-1-benzopyrano[3,2-b]pyridine-2-carboxylic acids, salts and esters of the formula: ##STR1## wherein R.sub.1 is hydrogen, lower alkyl, halogen, hydroxy or lower alkoxy; R.sub.2 is hydrogen, aralkyl or lower alkyl; R.sub.3 is hydrogen or lower alkyl and their pharmaceutically acceptable salts. These compounds are useful in the management of allergic conditions such as bronchial asthma, hay fever and so on.

Dependencies are inferred from the claim text.