Diazo Sentence Examples
From the primary amines are derived the diazo compounds and azo compounds; closely related are the hydrazines (q.v.).
The acid finds considerable use in organic chemistry, being employed to discriminate between the different types of alcohols and of amines, and also in the production of diazo, azo and diazo-amino compounds.
The diazo group takes up the para position with regard to the hydroxyl group, and if this be prevented it then goes into the ortho position.
The constitution of the isomeric diazo hydroxides has given rise to much discussion.
According to Hantzsch the isomeric diazo hydroxides are structurally identical, and the differences in behaviour are due to stereo-chemica l relations, the isomerism being comparable with that of the oximes.
The orthoand parasemidines can be readily distinguished by their behaviour with different reagents; thus with nitrous acid the ortho-semidines give azimido compounds, whilst the para-semidines give complex diazo derivatives; with formic or acetic acids the ortho-semidines give anhydro compounds of a basic character, the para-semidines give acyl products possessing no basic character.
Grandmougin (Berichte, 1891, 24, p. 2546) obtained azoimide from dinitraniline, C 6 H 3 (NO 2) 2 NH 2j by diazotization and conversion of the diazo compound into the perbromide, (NO 2) 2 C 6 H 3 N 2 Br 3.
Somewhat later, they found that it could be prepared from diazobenzene imide, provided a nitro group were present in the ortho or para position to the diazo group. The para-nitro compound is dropped slowly into a cold solution of one part of caustic potash in ten parts of absolute alcohol; the solution becomes dark red in colour and is then warmed for two days on the water bath.
When warmed with a solution of nitrous acid, they are converted into phenols; if, however, nitrous acid be added to an ice-cold solution of a primary amine in excess of mineral acid, a diazonium salt is formed (see Az o Compounds and DIAzO Compounds), or in absence of excess of acid, a diazoamine is produced.