[1H-pyrazolo/1,2-b/phthalazines with anti-inflammatory activity]

The synthesis of forty-one 2,2,6,7-substituted 2,3,5,10-tetrahydro-1H-pyrazolo[1,2-b]phthalazine-1,3-diones A) by reaction of 4,4-di-substituted pyrazolidine-3,5-diones with substituted or unsubstituted alpha,alpha'-dibromoxylene and B) by tetrahydrophthalazine and 2-substituted malonic acid chlorides is described. The antinflammatory activity was tested on carrageenan oedema in comparison with phenylbutazone.

Synthesis of some phthalazine derivatives chemically related to hydralazine

The potent antihypertensive properties of hydralazine and dihydralazine prompted the synthesis of sixteen new phthalazine derivatives with thiosemicarbazide or beta-propionamide residues to investigate their possible antihypertensive activity.

3-Hydroxymethyl-s-triazolo[3,4-a]phthalazine, a novel urinary hydralazine metabolite in man

The elucidation of the structure of a new major metabolic product of hydralazine, 3-hydroxymethyl-s-triazolo[3,4-a]-phthalazine, is described. The structures of several other previously described metabolites of the drug, phthalazone, s-triazolo[3,4-a]phthalazine, and 3-methyl-s-triazolo[3,4-a]phthalazine, are confirmed. A metabolic pathway of hydralazine is also proposed.

[Cyclic hydrazides. II. (1) Synthesis of 3-aminopyrazolo[1,2-b]hthalazine-1(1H),5(10 H)-diones]

The synthesis is described of a number of 3-aminopyrazolo[1,2-b]phthalazine-1(1H),5(10H)-diones (I) differently substituted on the amino group and in position 2, through condensation of alpha-chloro-beta-chlorocarbonylenamines (IV) with the 3,4-dihydrophthalazin-1(2H)-one (III). Alternatively cyanoacetylchlorides are condensed with (III) giving directly the 3-aminopyrazolo[1,2-b]phthalazine-1(1H),5(10H)-diones with the primary amino function (VII).