Synthesis of biologically active bridged diazabicycloheptanes.

The chemistry underlying how diazabicycloheptanes are assembled is described, subdivided according to chemical structure of two types, the 3,6 diazabicyclo[3.1.1]heptane and the 2,5-diazabicyclo[2.2.1]heptane ring system. Detailed information on myriad of activities of compounds derived from the two scaffolds are reported.

Preparation of thieno[3,2-h]cinnolinones as matrix metalloproteinase inhibitors.

A new series of thieno[3,2-h]cinnolinone analogues was synthesized which is structurally related to 2,3,4,4a,5,6-hexahydrothieno [3,2-h]cinnolin-3-one 1, a weak inhibitor of the matrix metalloproteinase MMP-8 (human neutrophil collagenase). Preliminary SAR studies have shown that while C4a-methyl, C7-acetylamino, C7 and C8-nitro substitution, and C4-C4a olefination provided no increase in activity relative to 1, C8-acetylamino substitution as in 5 and 8 was favourable. Moreover, to predict how the thieno[3,2-h]cinnolinone inhibitors might bind to MMP-8, the unsubstituted compound 9 was docked into the MMP-8 crystal structure. These studies revealed that inhibitor 9 does not seem to be able to coordinate the catalytically-active zinc ion but preferably interact with the peptide-binding region of the active site.

Synthesis, modelling, and mu-opioid receptor affinity of N-3(9)-arylpropenyl-N-9(3)-propionyl-3,9-diazabicycl.

A series of N-3-arylpropenyl-N-9-propionyl-3,9-diazabicyclo[3.3.1]nonanes (1a-g) and of reverted N-3-propionyl-N-9-arylpropenyl isomers (2a-g), as homologues of the previously reported analgesic 3,8-diazabicyclo[3.2.1]octanes (I-II), were synthesized and evaluated for the binding affinity towards opioid receptor subtypes mu, delta and kappa. Compounds 1a-g and 2a-g exhibited a strong selective mu-affinity with Ki values in the nanomolar range, which favourably compared with those of I and II. In addition, contrary to the trend observed for DBO-I, II, the mu-affinity of series 2 is markedly higher than that of the isomeric series 1. This aspect was discussed on the basis of the conformational studies performed on DBN which allowed hypotheses on the mode of interaction of these compounds with the mu receptor.

Synthesis and dopamine D2-like receptor binding affinity of substituted 5-phenyl-pyrrole-3-carboxamides.

A series of 5-p-substituted phenyl-pyrrole-3-carboxamide derivatives was designed as hybrid analogs of the dopamine D2-like 5-phenyl-pyrrole and heterocyclic carboxamide antipsychotics. The title compounds were synthesized and evaluated for dopamine D2-like receptor by means of [3H]YM-09151-2 receptor binding assay. The compound bearing a 1-ethyl-2-methyl-pyrrolidine moiety as the basic part of 5-phenyl-pyrrole-3-carboxamide derivative 1a together with its 2-chloro analog 1f were found to possess affinity in the low micromolar range. Substituted phenyl-pyrrolecarboxamides containing groups such as F, Cl, NO2, CH3, at the 4-position of the phenyl ring, gave ligands with lower D2-like affinity.

Synthesis and D2-like binding affinity of 4,5-dihydro-1H-benzo[g]indole-3-carboxamide derivatives as conformationally restricted 5-phenyl-pyrrole-3-carboxamide analogs.

A series of 4,5-dihydro-1H-benzo[g]-indole-3-carboxamide derivatives 2a-g were synthesized as conformationally restricted analogs of the dopamine D2-like 5-phenylpyrrole-3-carboxamide ligands and evaluated for their affinity for the dopamine D2-like receptors. In this series, N3-[(1-ethyltetrahydro-1H-2-pyrrolyl)methyl]-4,5-dihydro-1H-benzo[ g]indole- 3-carboxamide (2a) showed the highest affinity for D2-like receptors (IC50 = 160 nM). Replacement of the N-(1-ethyl-2-pyrrolidinyl)methyl side chain with a 2-(N,N-diethylamino)ethyl or a 1-benzyl-4-piperidinyl group (2b, 2d) decreased affinity for the D2-like receptor. The other compounds tested were found to be devoid of D2-like binding affinity.

Synthesis and pharmacological evaluation of 4,4a,5,6-tetrahydro-7,8-disubstituted-benzo[h]cinnolin-3(2H)-ones.

7,8-disubstituted-4,4a,5,6-tetrahydrobenzo[h]cinnolin-3(2H)-ones 2-4 have been synthesized and tested in comparison with the 8-acetylamino-4,4a,5, 6-tetrahydrobenzo[h]cinnolin-3(2H)-one 1 reported to be a potent antihypertensive and antithrombotic agent. Binding studies on phosphodiesterase (PDE) isoenzymes showed that the test compounds exhibited a modest affinity towards PDE III which in the case of 2, 3 was higher than that of 1. In vivo tests indicated that compounds 2 and 4 displayed lower hypotensive activity than model 1 while 3 was inactive. Conversely, compounds 2-4 were as potent as 1 in inhibiting collagen-induced platelet aggregation.

Synthesis and pharmacological evaluation of 5,6-dihydrobenzo[f] cinnolin-2(3H)ones analogues of antihypertensive and antiaggregating benzo[h]cinnolinones.

Two new dihydrobenzo[f]cinnolin-2(3H)ones (4a,b) have been synthesized and tested for their hypotensive, antihypertensive and antiaggregating activities in comparison with the lead 8-acetylamino-4,4a,5,6-tetrahydrobenzo[h]cinnolin-3(2H)-one 1. In vivo tests indicated that 4a,b displayed hypotensive and antihypertensive properties weaker than the model compound. On the contrary both compounds were more potent than 1 in inhibiting collagen-induced platelet aggregation.

Synthesis and pharmacological activity of 4-carbamoyl-6-beta-thienyl-4,5-dihydropyridazin-3-(2H)ones.

A new series of 4-carbamoyl-6-beta-thienyl-4,5-dihydropyridazin-3-(2H)ones 4a-g have been synthesized and tested for their anti-inflammatory and analgesic properties. Among the tested compounds, only 4f at 1 mmole/Kg showed antiinflammatory activity that was comparable with that of indomethacin (5 mg/Kg) though of shorter duration. Compounds 4a, 4e and especially 4g at 0.2 mmoles/Kg displayed relevant analgesic activity, 4g being the most potent derivative in the writhing test. Compounds 4c and 4g were found to possess analgesic activity also in the hot plate test.

Synthesis and pharmacological activity of 4-carbamoyl-5-aryl-6-methyl-4,5-dihydropyridazin-3(2H)-ones.

A new series of 4-carbamoyl-5-aryl-6-methyl-4,5-dihydropyridazin-3(2H)-ones have been synthesized and tested for their antiinflammatory and analgesic properties. Amongst the test compounds, only 31 showed antiinflammatory activity, though of shorter duration than that of indomethacin, taken as reference drug. On the contrary, many derivatives displayed relevant analgesic activity, 4--the only 4,5-dehydroderivative--being the most potent in the writhing test. In the hot plate test 3b, 3f and 3k were found to possess the most significant analgesic properties.

Synthesis and biological evaluation of substituted benzo[h]cinnolinones and 3H-benzo[6,7]cyclohepta[1,2-c]pyridazinones: higher homologues of the antihypertensive and antithrombotic 5H-indeno[1,2-c]pyridazinones.

Several substituted benzo[h]cinnolinones 3 and 3H-benzo[6,7]cyclohepta[1,2-c]pyridazinones 4, which were designed as less rigid congeners of 5H-indeno[1,2-c]pyridazinones 2, were synthesized and tested as antihypertensive, inotropic, antithrombotic, antiinflammatory, and antiulcer agents. While the seven-membered ring derivatives displayed only antithrombotic properties, which were comparable to that of acetylsalicylic acid, most of the benzo[h]cinnolinones exhibited significant antihypertensive, inotropic, and antithrombotic properties. In this respect, the 8-amino (3b) and 8-acetylamino (3c) together with the 4,4a-dehydro analogue of 3c (11) were found to possess the most potent and long-lasting antihypertensive activity. In particular, the dextro isomer of 3c was more active than the racemic form, with lower tachycardiac effects. Unlike the lower homologues 2, none of the compounds showed significant antiinflammatory or antiulcer activity.

Synthesis and pharmacological study of 5-aryl-6-methyl-4,5-dihydro-pyridazin-3(2H)ones and related 5-aryl-6-methyl-pyridazin-3(2H)ones.

New 5-aryl-6-methyl-4,5-dihydropyridazin-3(2H)ones (III) and related 5-aryl-6-methyl-pyridazin-3(2H)ones (IV) were synthesized in order to evaluate their pharmacological profile in comparison with that of the known class of antihypertensive and platelet aggregation inhibitors 5-methyl-6-aryl-4,5-dihydropyridazin 3(2H)ones (I). Though none of the tested derivatives was found to possess the antihypertensive potency of the reference compounds, some of them displayed significant antithrombotic and antiulcer properties. In particular, 5(p. acetylaminophenyl)-6-methyl-pyridazin-3-one (IV c) was found highly effective (ED50 = 1.2 mg/kg) in inhibiting indomethacin-induced ulcers.

Antihypertensive and antithrombotic activities of 6-(substituted phenyl)-5-hydroxymethyl-4,5-dihydro-3(2H)pyridazinones.

The synthesis of a series of 6-(4R-phenyl)-5-hydroxymethyl-4,5-dihydro-3(2H)pyridazinones is reported. The compounds were evaluated for their oral antihypertensive activity in rats and some of them [(V b), R = NH2] and [(V c), R = NHCOCH3] were found to induce a high decrease in systolic blood pressure. Moreover all the compounds displayed an antithrombotic activity comparable to, or greater than, that of ASA.

[C-alkylpiperazines. XII. Synthesis and diuretic activity of compounds structurally related to clopamide]. / C-alchilpiperazine. Nota XII--Sintesi ed attività di composti strutturalmente correlabili alla clopamide.

The synthesis and diuretic activity were reported of a series of N1-(4-chloro-3-sulfamoylbenzamide)-N4-alkylpiperazines, 2-methyl- and cis-2,6-dimethyl substituted, structurally related to clopamide, as well as of two N4-alkyl-N1-(4-chloro-3-sulfamoylbenzoyl)-2-methyl-1,2,3, 4-tetrahydroquinoxalines. In the piperazine series the presence of methyl group in position 2 and 6 of the piperazinic ring was found to increase the diuretic potency of the C-unmethylated compound.

Rigid congeners of arylpyridazinones. IV. Synthesis and activity of derivatives of the new heterocyclic system 9H-indeno[2,1-c]pyridazine.

Representative terms of the new heterocyclic system 9H-indeno[2,1-c]pyridazine have been synthesized. Their antiinflammatory, analgesic and antipyretic activities were evaluated, in order to compare the pharmacological profiles with those of the isomeric series of 5H-indeno[1,2-c]pyridazine previously investigated. The new compounds were, in general, equiactive as analgesic but less active as antiinflammatory and antipyretic agents with respect to their 5H-isomers.

6-Halogen derivatives of 2-(3-benzoylphenyl)propionic acid.

The synthesis of the 6-fluoro (I a), 6-chloro (I b) and 6-bromo (I c) derivatives of the known antiinflammatory agent 2-(3-benzoylphenyl)propionic acid (ketoprofen) is reported. The procedure employed involves the direct phase-transfer methylation of the appropriate arylacetonitriles and the subsequent hydrolysis of the alpha-methyl arylacetonitriles (V) thus obtained. It is noteworthy that (V b) and (V c) were not accompanied by alpha, alpha-dimethylated contaminants, owing to the steric hindrance of the chloro and bromine substituent. The pharmacological evaluation of (I a-c) showed that the presence of the halogen unexpectedly abolished the antiinflammatory and antipyretic activities of the model drug. The 6-ethoxy derivative (I d), isolated as by-product of the synthesis of (I a) was also found inactive. A hypothesis has been formulated on the loss of activity of these compounds.

[Unexpected anti-inflammatory activity of rigid structure derivatives of 6-arylpyridazinone antihypertensives. I. Synthesis and activity of 4,4a-dihydro-5H-indeno[1,2c]pyridazin-3-ones]. / Inattesa attività antiinfiammatoria di strutture rigide derivate da 6-arilpiridazinoni antiipertensivi. Nota I-Sintesi e attività di 4,4a-diidro-5H-indeno[1,2-c]piridazin-3-oni.

The antihypertensive 5-methyl-6-p.cyanophenyl-4,5-dihydro-3(2H)-pyridazinone has been embodied in a rigid framework corresponding to a 4,4a-dihydro-5H-indeno[1,2-c]-3-pyridazinonic structure (II). The resulting 7-cyano derivative (IIc) was found to be devoid of antihypertensive activity. However this compound, as well as other members having structure (II), exhibited antiinflammatory properties.