Ethyl carbazate

Chemical properties

Off-white crystals.

The Uses of Ethyl carbazate

Prepare 4-phenylurazole from ethyl carbazate and then oxidize the urazole with gaseous dinitrogen tetroxide to yield 4-phenyl-1,2,4-tri- azoline-3,5-dione la. Modification of the ethyl carbazate procedure in which analytically pure monoalkylhydrazine hydrochlorides were isolated in greater than 90% yield, starting from a ketone or aldehyde. Treatment of primary amines is with chloroamine or hydroxylamine-0-sulfonic acid and the condensation of a carbonyl compound with ethyl carbazate. The FeCl 3 -catalyzed reaction of ethyl carbazate (2 b) proceeded readily to give β-hydroxyester 3 b in better yield. A new one-pot neat synthesis of some 5-aryl-2,4-dihydro-3H-1,2,4-triazol-3-ones through cyclocondensation of ethyl carbazate with aryl nitriles catalyzed by DMAP as an efficient and basic nucleophilic catalyst is described.

The Uses of Ethyl carbazate

Synthetic intermediate.

Hazard

Irritant.

Purification Methods

Fractionate the carbazate using a Vigreux column (p 11) until the distillate crystallises [Allen & Bell Org Synth Coll Vol III 404 1955, Beilstein 3 IV 174].