Research on heterocyclic compounds. XXX. Synthesis and pharmacological activity of 2-methylimidazo[1,2-b]pyridazine-3-carboxylic acids.

A group of ethyl 2-methylimidazo[1,2-b]pyridazine-3-carboxylates were prepared by reaction in anhydrous ethanol of some substituted 3-amino-pyridazines with ethyl 2-chloroacetoacetate. The corresponding carboxylic acids were obtained via alkaline or acid hydrolysis and then tested both in vivo to evaluate their antiinflammatory, analgesic and ulcerogenic actions and in vitro for their ability to inhibit the prostaglandin biosynthesis. The pharmacological results are discussed in terms of both structure-activity relationships and mechanism of action.

1-Acyl-, 3-acyl- and 1,3-diacyl-3-furfuryl-1-phenylthioureas with platelet antiaggregating and other activities.

The synthesis in excellent yields of 1-acyl-3-furfuryl-1-phenylthioureas 2 by reacting at t less than or equal to 10 degrees C 3-furfuryl-1-phenylthiourea 1, prepared in situ from furfurylamine and phenyl isothiocyanate, with aromatic or heterocyclic acyl chlorides in pyridine solution is described. 1-Acylthioureas 2 rearranged in high yields to 3-acylthioureas 3 by treatment with sodium hydroxide in heterogeneous phase. 1,3-Diacyl-3-furfuryl-1-phenylthioureas 4 were obtained in satisfactory yields by treatment of 1 with two moles of acyl chloride as in the case of 1-monoacylation. The thiourea 1 prepared in situ reacted with iodomethane in dimethylformamide solution and in the presence of sodium hydride to give in high yield the S-methyl derivative, namely the methyl ester of N-phenyl-1-furfurylaminethiocarboximidic acid. Some acylthioureas 2 and 4 showed a platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid. The 1,3-diacylthiourea 4 c exhibited an appreciable anticonvulsant activity in mice and some compounds 2 and 4 moderate competitive antiacetylcholine and H1-antihistamine effects in vitro.

omega-Dialkylaminoalkyl esters of 3-dialkylamino-4,7,7-trimethyl-N-phenylbicyclo[2.2.1] hept-2-ene-2-iminothiolic acids with local anesthetic activity.

A series of omega-dialkylaminoalkyl esters of 3-dialkylamino-4,7,7-trimethyl-N-phenylbicyclo[2.2.1]hept-2-ene-2- iminothiolic acids 3 was prepared by reaction of 4,7,7-trimethyl-3-(dimethylamino or 1-piperidinyl)-N-phenylbicyclo[2.2.1] hept-2-ene-2-thiocarboxamides with a number of omega-chloroalkyldialkylamines in the presence of sodium hydride in DMF or benzene solution. Some esters 3 showed an appreciable local anesthetic activity in mice.

Preparation and pharmacological activity of some 1-lupinylbenzimidazoles and 1-lupinylbenzotriazoles.

Twelve new 1-lupinyl-benzimidazole and 1-lupinyl-benzotriazole derivatives were prepared and, together with some previously described analogues, were tested for analgesic (hot plate test), antiinflammatory (against carrageenan edema), diuretic and antihypertensive (in spontaneously hypertensive rats) activities. Several compounds exhibited a good degree of activity in one or in more than one areas.

5-[4-(omega-dialkylaminoalkoxy)phenylmethylene] -1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones with platelet antiaggregating and other activities.

The synthesis of 5-[4-(omega-dialkylaminoalkoxy)phenylmethylene]- 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones 3 by reaction of some 4-(omega-dialkylaminoalkoxy)benzaldehydes with (+)-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-one in the presence of sodium methoxide is described. Some aminoethers 3 showed platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as weak antiarrhythmic activity in rats and moderate infiltration anesthesia in mice.

2H-pyrano[3,2-d]-1-benzoxepin derivatives with platelet antiaggregating and other activities.

The synthesis of some N,N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-pyrano[3,2-d]-1-benzoxepin-2 -ones by reaction of phenylchloroketene with a series of N,N-disubstituted (E)-4-aminomethylene-3,4-dihydro-1-benzoxepin-5(2H)-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. Some of these compounds showed a platelet antiaggregating activity in vitro slightly superior to that of acetylsalicylic acid, as well as weak local anesthetic and antiinflammatory activities in mice and rats, respectively.

Benzo[6,7]cyclohepta[1,2-b]pyran derivatives with platelet antiaggregating and other activities.

The synthesis of some N,N-disubstituted 4-amino-6,7-dihydro-3-phenylbenzo[6,7]cyclohepta[1,2-b]pyran-2(5H) -ones by reaction of phenylchloroketene with a series of N,N-disubstituted 6-aminomethylene-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. Some compounds showed a platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as a weak local anesthetic activity in mice and antiinflammatory activity in rats.

3,5-Diphenyl-1H-pyrazole derivatives. VIII. N-substituted 3-(4-hydroxy-3,5-diphenyl-1H-pyrazol-1-yl)-propanamides, -propanamines and 2-(4-hydroxy-3,5-diphenyl-1H-pyrazol-1-yl)ethanamines with platelet antiaggregating, hypotensive, antiarrhythmic and other activities.

The synthesis of N,N-disubstituted 3-(4-hydroxy-3,5-diphenyl-1H-pyrazol-1-yl)-propanamides and -propanamines, starting from 4-benzoyloxy-3,5-diphenyl-1H-pyrazole, and of N-substituted 2-(4-hydroxy-3,5-diphenyl-1H-pyrazol-1-yl)ethanamines, starting from 4-acetoxy-1-(2-hydroxyethyl)-3,5-diphenyl-1H-pyrazole, is described. Some of the above compounds showed a platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as moderate hypotensive, antiarrhythmic, local anesthetic, sedative and antiinflammatory activities in rats and mice.

3,3-disubstituted 1-acyl-1-phenylthioureas with platelet antiaggregating and other activities.

This paper describes the synthesis in excellent yields of N-acyl-N-phenyl-1-pyrrolidine-, 1-piperidine-, 4-morpholine-, 1,2,3,4-tetrahydro-1-quinoline-, 1,2,3,4-tetrahydro-2-isoquinoline-, 10-phenothiazine- and 2,2'-dipyridylamine-carbothioamides by reaction of the corresponding 3,3-disubstituted 1-phenylthioureas, prepared in situ from the appropriate secondary amine and phenylisothiocyanate, with aromatic or heterocyclic acyl chlorides in pyridine solution or, in lower yields, in anhydrous dimethylformamide or pyridine solution in the presence of sodium hydride. N-phenyl-1-pyrrolidinecarbothioamide prepared in situ reacted with iodomethane in dimethylformamide solution and in the presence of sodium hydride to give excellent yield of the S-methyl derivative, namely the methyl ester of N-phenyl-1-pyrrolidinethiocarboximidic acid. Some of the above compounds, in particular the phenothiazine acylthioureas, showed platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid; moreover, some acylthioureas exhibited moderate hypoglycemic activity in rats and competitive antiacetylcholine and H1-antihistaminic effect in vitro inferior to that of atropine and chlorpheniramine, respectively.

2H-pyrano[2,3-f]quinazoline derivatives with platelet antiaggregating and other activities.

The synthesis of some N,N-disubstituted 4-amino-5,6-dihydro-3,8-diphenyl-2H-pyrano[2,3-f]quinazolin- 2-ones by the reaction of phenylchloroketene with a series of N,N-disubstituted (E)-6-aminomethylene-7,8-dihydro-2-phenylquinazolin-5(6H)-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. The methylbenzylamino and diphenylamino derivatives showed platelet antiaggregating activity in vitro superior to that of acetylsalicylic acid. The 1-pyrrolidinyl derivative showed appreciable local anesthetic activity in mice, whereas the whole series of compounds exhibited weak antiinflammatory activity in rats.

omega-Dialkylaminoalkyl ethers of 6-(benzyl or phenyl)-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-ol with platelet antiaggregating and local anesthetic activities.

The synthesis of 1,3,3-trimethyl-6-phenyl-2-oxabicyclo[2.2.2]octan-6-ol 2 and 6-benzyl-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ol 3 starting from (+)-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-one and phenylmagnesium bromide or benzylmagnesium chloride, respectively, is described. Alcohols 2 and 3 gave a series of omega-dialkylaminoalkyl ethers 4 by reaction as sodium salts with omega-chloroalkyldialkylamines in toluene solution. Some compounds 4, in particular those derived from alcohol 2, showed a strong platelet antiaggregating activity in vitro, superior to that of acetylsalicylic acid, as well as in general an appreciable local anesthetic activity and a weak sedative effect in mice.

omega-Dialkylaminoalkyl ethers of 5-endo-dialkylamino-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-hydroxyimines with platelet antiaggregating, antiarrhythmic and local anesthetic activities.

The synthesis of 1,3,3-trhimethyl-5-endo-(1-piperidinyl)- and -5-endo-(4-morpholinyl)-2- oxabicyclo [2.2.2]octan-6-hydroxyimine 3 and 4 starting from 5-endo-bromo-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-hydroxyimine+ ++ and excess piperidine or morpholine is described. Compounds 3 and 4 gave a series of omega-dialkylaminoalkyl ethers 5 by reaction as sodium salts with omega-chloroalkyldialkylamines in DMF solution. Some of aminoethers 5 showed in mice an appreciable antiarrhythmic and local anesthetic activity, as well as a platelet antiaggregating activity in vitro comparable to that of acetylsalicylic acid.

3,5-Diphenyl-1H-pyrazole derivatives. VII--Esters, 2-dialkylaminoethyl ethers and N-substituted carbamates of 1-(2-hydroxy-3-phenoxypropyl)-3,5-diphenyl-1H-pyrazole with depressant and platelet antiaggregating activities.

The syntheses of 1-(2-hydroxy-3-phenoxypropyl)-3,5-diphenyl-1H-pyrazole 2 by reaction of 1-hydrazino-3-phenoxy-2-propranolol with dibenzoylmethane, of esters 3 and 2-dialkylaminoethyl ethers 4 starting from 2 as sodium salt and acyl chlorides or 2-chloroethyldialkylamines, respectively, as well as of N-aryl carbamates 5 by reaction of 2 with aryl isocyanates, are described. Some of the above compounds showed a considerable sedative effect in mice and a remarkable platelet antiaggregating activity in vitro, as well as moderate local anesthetic, analgesic and antiinflammatory activities in mice and rats.

3,5-Diphenyl-1H-pyrazole derivatives. III--Esters from 1-(2-hydroxyethyl)-3,5-diphenyl-1H-pyrazole and its 4-bromo derivative with hypotensive, depressant, antiarrhythmic and analgesic activities.

The synthesis of dialkylaminoalkyl ethers (III a-g) by reaction of 1-(2-hydroxyethyl)-3,5-diphenyl-1H-pyrazole (I) sodium salt with a series of omega-chloroalkyldialkylamines is described. Cyanoethylation of alcohol (I) and its 4-bromo derivative (II) gave 2-cyanoethyl ethers (III h, i), one of which (III h) was hydrolyzed to the corresponding carboxylic acid. Cyanoethylation of 3,5-diphenylpyrazole (IV) and its 4-bromo derivative (V) yielded nitriles (VI) and (VII), respectively, which were hydrolyzed to the corresponding carboxylic acids (VIII) and (IX). Some of the above compounds showed considerable hypotensive, depressant, antiarrhythmic and analgesic activities in mice and rats, as well as a remarkable platelet antiaggregating activity in vitro. Moreover, the above compounds usually exhibited a moderate antiinflammatory activity in rats and infiltration anesthesia in mice.

Influence of rat prenatal and postnatal exposure to a non-steroidal anti-inflammatory agent (flunoxaprofen) on cardiovascular function in the progeny.

The present experiments evaluated in rats the effects of prenatal and postnatal exposure to a non-steroidal antiinflammatory agent, flunoxaprofen (5-10 and 20 mg/kg/day by the oral route), on cardiovascular function in the pups. In both conscious and anaesthetized rats pre- and postnatal flunoxaprofen exposure at the 30th and 60th day of age, significantly (P less than .05) induced a decrease of pressor response to carotid-sinus baroreceptor stimulation and to L-noradrenaline (0.1-1 and 5 micrograms/kg iv), and an increase of the hypotensive responses to L-isoprenaline (0.01-0.1 and 1 microgram/kg iv) and acetylcholine (0.01-0.1 and 1 microgram/kg iv). These effects were not observed in rats on the 90th day of age. Moreover, pre- and postnatal flunoxaprofen exposure did not modify systolic arterial blood pressure of plasma levels of catecholamines and acetylcholinesterases. Our results also show that in normotensive rats flunoxaprofen exposure during pregnancy did not affect the body weight, systolic or diastolic blood pressure or heart rate of pregnant rats. It did not affect the length of gestation, number of pups per litter or pup body weight. No macroscopic teratogenic effects were observed.

[Preparation and pharmacologic activity of N-oxides of 4'-(benzotriazol-2-yl-phenylalkanoic and -phenoxyalkanoic acids]. / Preparazione e attività farmacologica di n-ossidi di acidi 4'-(benzotriazol-2-il)-fenilalcanoici e-fenossialcanoici.

A number of N-oxides of 4'-(benzotriazol-2-yl)-phenylalkanoic and -phenoxyalkanoic acids bearing various substituents on position 6 of benzotriazole together with 4'-(benzotriazol-2-yl) phenylacetic acid were prepared and subjected to a wide pharmacological screening. Several compounds exhibited significant antiinflammatory and diuretic activities, while one was endowed with antihypertensive activity.

Evidence of muscarinic receptor subtypes in airway smooth muscle of normal volunteers and of chronic obstructive pulmonary disease patients.

Since there have been only a few studies on muscarinic receptor subtypes in airway smooth muscle, the effect was investigated of pirenzepine on airways of patients with chronic obstructive pulmonary disease (COPD) and the functional responses compared from these patients with those from healthy subjects. Our data demonstrated that the therapy with pirenzepine significantly improved ventilatory function in patients with COPD. The data also suggested that this drug exerts its action on small airways, but not larger airways in normal subjects. It is possible that in healthy human beings pirenzepine produces mild bronchodilation by means of a vagal efferent blockade, while in patients with COPD, it may be effective because it not only decreases the activity of the vagal efferent pathway, but also decreases the sensitivity of vagal sensory endings and causes a vagal afferent blockade.

[Synthesis and pharmacologic activity of 9-R-octahydroindolo[2,3-a]quinolazine]. / Sintesi ed attività farmacologica di 9-R-ottaidroindolo [2,3-a]chinolizine.

By acid induced cyclization of quinolizidin-1-one 4-R-phenylhydrazones several derivatives of 1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine (1), bearing a substituent on position 9, were prepared. When R = Cl this reaction gave rise also to a red-orange compound to which the structure (V) of 1-(p-chloro)phenylazo-3,4,6,7,8,9-hexahydroquinolizine was assigned. Substances (1 b)-(1-f) were tested for spontaneous locomotor, muscle relaxant, analgesic, antiinflammatory, diuretic and cardiovascular activities and for influence on pentylentetrazole and sodium pentobarbital actions. Interesting levels of activity were exhibited in several cases.