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

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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.

The reaction of 1-acetyl-2-phenylhydrazine with ethoxymethylenemalononitrile yielded [(4-cyano-1-phenylpyrazol-3-yl)aminomethylene]propanedinitrile. Hydrolysis followed by annulation with methyl isocyanate provided a synthetic route to 2-phenylpyrazolo[3,4-d]pyrimidines.

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.

This paper presents a number of qualitative and semi-quantitative observations on the effect of small concentrations of water on the polymerizations of butyl cyanoacrylates by tertiary amines in THF. It reports also that, in the absence of other bases, large concentrations (approx. 1 mol/l) of water can cause the polymerization of ethyl cyanoacrylate, in THF, even in presence of normally inhibiting amounts (10−5 mol/l) of p-toluenesulfonic acid. A formal kinetic scheme of a stationary-state polymerization, initiated by hydroxyl anions, is presented and discussed.

An adhesive composition consisting essentially of (A) an alkyloxyalkyl 2-cyanoacrylate represented by the formula

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