Any of a class of compounds (mostly yellow crystalline solids) whose molecules contain two adjacent hydrazone groups (\\\\\\C=N—NH2 or a substituted derivative).
Osazones are formed characteristically when compounds containing the groups —CO—CH(OH)— or —CO—CO— (such as sugars) react with phenylhydrazine..
Origin
Late 19th century; earliest use found in Journal of the Chemical Society. From German Osazon from -ose + azo- + -on.