Gap Cure

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.

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

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.

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.

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 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.

Gap-filling cyanoacrylate adhesives containing cyanoacrylate esters and organic halogenated polymers with a K-value of at least 46.

Adhesive composition comprising: A. at least one monomeric ester of 2-cyanoacrylic acid, and B. at least one polymerisation initiator selected from caffeine and theobromine

A 2-cyanoacrylate composition useful as an adhesive contains a Lewis acid metal salt comprising a metal such as aluminum, gallium, indium or thalium, and the conjugate base of an acid such as a monohalo-, dihalo- or trihalo-acetate (e.g. aluminum trifluoroacetate salt). A clathrate such as a crown ether is also present.

A 2-cyanoacrylate composition useful as an adhesive contains a Lewis acid metal salt comprising a metal such as aluminum, gallium, indium or thalium, and the conjugate base of an acid such as a monohalo-, dihalo- or trihalo-acetate (e.g. aluminum trifluoroacetate salt). A clathrate such as a crown ether is also present.