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.
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Applications
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.
Solubility
Very soluble in water.
Notes
Store in cool place. Keep container tightly closed in a dry and well-ventilated place. Store away from strong oxidizing agents.
RUO – Research Use Only
General References:
- A. Davoodnia,; M. Bakavoli,; M. Soleimany,;H. Behm. A new one-pot neat synthesis of 1,2,4-triazol-3-ones through 4-(N,N-dimethylamino) pyridine (DMAP) catalyzed cyclocondensation of ethyl carbazate with aryl nitriles. Chinese Chemical Letters. 2008, 19 (6),685-688.
- N. I. Ghali,; D. L. Venton,; S. C. Hung,; G. C. Le Breton. High-yielding synthesis of monoalkylhydrazines. J. Org. Chem., . 1981, 46 (26), 5413-5414.
- Forms crystalline ethoxycarbonyl hydrazones with aldehydes and ketones. With o-acylphenols, Pb(OAc)4 treatment of the resulting hydrazone results in replacement of the phenolic OH with ethoxycarbonyl, providing a route to ethyl o-acylbenzoates: Tetrahedron Lett ., 31, 6781 (1990).
- Reaction with methyl ketones, followed by treatment with SOCl2, leads to 4-substituted 1,2,3-thiadiazoles: J. Am. Chem. Soc., 77, 5359 (1955). In the presence of base, these readily lose N2 to give alkynethiolates: Can. J. Chem., 46, 1057 (1968):
- More recently, this sequence has been used in the synthesis of dendrimers from 1,3,5-triacetylbenzene: J. Chem. Soc., Perkin 1, 2203 (1994).