A common way to produce the 3-azidocoumarin is by condensation of salicylaldehyde and N-acetylglycine or nitroacetate. The intermediate is trapped with sodium azide to produce the 3-azidocoumarin. The isomeric 4-azidocoumarin (CAS# 42373-56-8) product can also be prepared from 4-hydroxycoumarin via the 4-chloro derivative, which reacts with sodium azide.