Technical documentation

Microwave-Assisted and Continuous Flow Multistep Synthesis of 4-(Pyrazol-1-yl)carboxanilides

By: 
David Obermayer
Toma N. Glasnov
C. Oliver Kappe

Potential Purine Antagonists. VI. Synthesis of 1-Alkyl- and 1-Aryl-4-substituted Pyrazolo[3,4-d]Pyrimidines

By: 
C. C. Cheng
Roland K. Robins

Various monosubstituted hydrazines have been reacted with ethoxymethylenemalononitrile to yield the corresponding l-substituted-5-amino-4-cyanopyrazolcs (IV). Treatment of IV with concentrated sulfuric acid gave the corresponding l-substituted-5-aminopyr~zole-4carbosmides (XVI). The structure of 5-amino-1-phenylpyrazole-4-carbosamidewas established by an unambiguous synthesis. The preparation of 1-alkyl- and l-argl-l-aminoayrazolo[3,4-d]pyriniidineshas been accomplished by treating the corre- sponding 1-alkyl(or aryl)-5-amino-4-cyanopyrazole (IV) with boiling formamide.

Über die Darstellung des 1-Phenyl-8-Pyrazolons

By: 
A. Michaelis
E. Remy

The Condensation of Aminoantipyrine. III (1). The Synthesis of Methylrubazoic Acid

By: 
Edgar Emerson
Lindley Clair Beegle

Investigation of Pyrazole Compounds. I. The Reaction Product of Phenylhydrazine and Ethyl Cyanoacetate

By: 
A. Weissberger
H. D. Porter

Conrad and Zart' treated ethyl cyanoacetate with phenylhydrazine, using sodium alcoholate as a condensing agent, and obtained a colorless compound of the composition C9H9N30and the m. p. 219". This, they assumed to be l-phenyl-3- hydroxy-5-pyrazolone-imide,I. However, the reaction between ethyl cyanoacetate and phenyl- hydrazine could also lead to the isomeric l-phenyl- 3-amino-5-pyrazolone, 11.

Utility of cyanoacetic acid hydrazide in heterocyclic synthesis

By: 
Samir Bondock
Abd El-Gaber Tarhoni
Ahmed A. Fadda

This review describes the synthesis and reactions of cyanoacetic acid hydrazide as building block for the synthesis of polyfunctionalized heterocyclic compounds with pharmacological interest.

Investigation of Pyrazole Compounds. II. The Synthesis of 1-Phenyl-3-hydroxy-5-pyrazolone Imide

By: 
A. Weissberger
H. D. Porter

In the first paper of this series it was shown that the compound synthesized by Conrad and Zart and called 1-phenyl-3-hydroxy-5-pyrazoloinmeide is in fact the isomeric l-phenyl-3-amino-5-pyrazlone I. The real l-phenyl-3-hydroxy-5-pyrazolone imide I1 has now been prepared. Phenylhydrazine was condensed with cyanoacetyl chloride to give 0-cyanoacetylphenylhydrazine 111. In- stead of the acid chloride, cyanoacetazide3can be used, giving a somewhat higher yield. I11 is a colorless well-crystallizing substance.

New Pyrazolo-Pyrimidines

US3098075
By: 
Jean Druey
Paul Schmidt
Kurt Eichenberger

This invention relates to a new pyrazolo-pyrimidines and a process for their preparation. More particularly the invention concerns hydro-pyrazolo (3,4-d) pyrimidines having the nucleus of the formula

-

which contain at least one of the positions 4 and 6 an oxo group and are alkylated, oxyalkylated, e.g. oxyethylated or cycloalkylated at at leats one ring nitrogen atom, their tautomeric forms and salt thereof.

Ueber Methyl- und Aethyloxalessigester

By: 
E. Arnold

Homologe des in der vorhergehenden Mittheilung beschriebenen Oxalessigesters lassen sich gewinne, wenn man den Oxalsäureester mit den höreren Fettsäureestern in Reaction bringt.

The Reaction of Esters with Phenylhydrazine in the Presence of Phosphoric Acid

By: 
T. O. Jones
R. E. Halter
W. L. Myers

The reaction of esters with ammonia, hydroxylamine and hydrazine to produce the corresponding amide, hydroxamic acid or hydrazide are well known. Cohn and Meyer reported a reaction between methyl salicylate and phenylhydrazine, and Baidakowski, Reformatski and Slepak prepared a few phenyhydrazitdes by heating the ester and phenylhydrazine in a sealed tube at 210°, but no other examples of this reaction have since been reported.

 

Pages