Studies on antianaphylactic agents. 7. Synthesis of antiallergic 5-oxo-5H-[1]benzopyrano[2,3-b]pyridines

5-Oxo-5H-[1]benzopyrano[2,3-b]pyridine-3-carboxylic acids 23 and their tetrazole analogues 24 were synthesized from 4-oxo-4H-1-benzopyran-3-carbonitriles 3 or 2-amino-4-oxo-4H-1-benzopyran-3-carboxaldehydes 4. When administered intravenously, they exhibited antiallergic activity in a reaginic PCA test in rats. In the carboxylic acid series, the activity was influenced by the substituents at the 2-position and increased substantially in the following order: Me, OMe less than NH2 less than OH, H less than NHOMe. On the other hand, in the tetrazole series, 2-unsubstituted derivatives showed the highest activity. Regardless of the kinds of substituents at positions 2 and 3, compounds bearing an alkyl group, especially an isopropyl group at the 7-position, were superior in activity to the corresponding unsubstituted compounds. Among these alkyl derivatives, 3-carboxylic acid derivatives, i.e., 23c (7-ethyl), 23g (2-amino-7-isopropyl), 23r [2-(methoxyamino)-7-isopropyl], and a 3-tetrazole derivative 24c (7-isopropyl), were 41-184 times as potent as disodium cromoglycate. They also exhibited remarkable activity when administered orally; clinical studies on 23g (AA-673) are in progress.     

2H-[1]benzopyrano[3,4-b]pyridines: synthesis and activity at central monoamine receptors

Two general synthetic approaches to a novel series of 2H-[1]benzopyrano[3,4-b]pyridines are described together with their receptor binding profile at a variety of monoamine receptors in mammalian brain tissue. The biologically active members of this series fall into into one of two broad classes: 3,4,4a,5-tetrahydro-2H-[1]benzopyrano[3,4-b]pyridines or trans-1,3,4,4a,5,10b-hexahydro-2H-[1]benzopyrano[3,4-b]pyridines. By appropriate pharmacophoric modification potent selective ligands for D2, alpha-2, 5HT1A, and 5HT2 receptors may be obtained. The previously published in vivo data on certain key representatives of these series are also summarized.     

Synthesis of novel 1-pyrazolylpyridin-2-ones as potential anti-inflammatory and analgesic agents

A new series of 4-alkyl/aryl-2-oxo-1-pyrazolyl-1,2-dihydropyridine-3-carbonitriles, pyrazolo[3,4-b]pyridine-5-carbonitriles and pyrido[2,3-d]pyrimidine-6-carbonitriles have been synthesized and tested for their anti-inflammatory and analgesic activities. Among the tested compounds, 3e and 8b exhibited comparable anti-inflammatory activity to the standard (indomethacin). Compounds 5, 7a, and 8b displayed potent analgesic activity. Detailed syntheses, spectroscopic and biological data are reported.     

5-羟基-5H-[1]-苯并吡喃[2,3-b]吡啶的制备

目的改进5-羟基-5H-[1]-苯并吡喃[2,3-b]吡啶的合成工艺。方法以2-氯烟酸为起始原料,经亲核取代、环合和还原制得目标化合物。结果总收率68.6%,产物经熔点和1HNMR确证。结论改进后的工艺具有操作简便,对环境友好,收率高等优点。     

Synthesis and properties of 2H-2-(4-substituted -1-piperazinylalkyl)-4,6-dimethyl-3-oxo-2,3-dihydroisothiazolo [5,4-b] pyridines

The preparation of a number of derivatives of 2H-4,6-dimethyl-3-oxo-2,3-dihydroisothiazolo [5,4-b] pyridine (1) containing 4-methyl(phenyl, heteroaryl)-1-piperazinylalkyl moiety by two routes has been described. Preliminary results of pharmacological screening of compounds synthesized showed antipsychotic activity of 2H-2-13-(4-phenyl-1-piperazinyl)propyl-3-oxo-2,3-dihydroisothiazolo [5.4-b] pyridine (4f).     

Reaktionen an Heterocyclen mit 2-Acyl-2-propenon-Teilstruktur, 6. Mitt. Zur Synthese von 6-Oxo-6H-[1]benzopyrano[4,3-b]chinolinen

Reactions on Heterocycles Containing 2-Acyl-2-propenone Structure, VI: A Novel Preparation of 6-Oxo-6H-[1]benzopyrano[4,3-b]quinoline Derivatives The 4-chloro-2-oxo-2H-chromene-3-carbaldehydes 1 and 2 react with aromatic amines 3 to the 6-oxo-6H-[1]benzopyrano[4,3-b]quinolines 6 and 7 the structure of which is assured by an unambiguous synthesis — vilsmeier reaction of 4-phenylaminocoumarines 12 .     

Synthesis and antifungal activity of novel pyrano[2',3':4,5]thiazolo[2,3-b]quinazolines, pyrido[2',3':4,5]thiazolo[2,3-b]quinazolines and pyrazolo[2',3':4,5]thiazolo[2,3-b]quinazolines

The starting materials thiazolo[2,3-b]quinazolines (5a,b) were obtained in one pot synthesis by treating octahydroquinazoline (2) with chloroacetic acid and aromatic aldehydes. Thiazoloquinazoline (5) was reacted with CH2(CN)2/piperidine and CH2(CN)2/NaOH (CH3OH), to furnish pyrano[2',3':4,5]thiazolo[2,3-b]quinazolines (6a,b) and pyrido[2',3':4,5]thiazolo[2,3-b]quinazoline (7), respectively. Refluxing of 5a with NH2CSNH2/KOH and hydrazines in ethanol furnished the corresponding, [1,3]thiazino[4'5':4,5]thiazolo[2,3-b]quinazoline (10) and pyrazolo[3',4':4,5]thiazolo[2,3-b]quinazolines (11a,b), respectively. Antifungal activity was shown for some of the synthesized compounds.     

Synthesis of 6,7-dialkoxy-2-arylmethylidene-2,3- dihydrobenzo[4,5]imidazo[2,1-b][1,3]thiazol-3-ones exhibiting anti-inflammatory activity

New 6,7-dialkoxy-2-arylmethylidene-2,3- dihydrobenzo[4,5]imidazo[2,1-b][1,3]thiazol-3-ones (3a-h, 4b, c, e, g) were synthesized from 2-(5,6-dialkoxy-1H-benzo[d]imidazol-2-ylsulfanyl)acetic acids (1, 2) and corresponding aromatic aldehydes in acetic anhydride. The compounds 3e, f and 4b, g were also synthesized from corresponding aromatic aldehydes and 6,7-dialkoxy-2,3-dihydrobenzo[4,5]imidazo[2,1-b][1,3]thiazol -3-ones (5, 6) obtained by the cyclization of the acids 1 and 2 in acetic anhydride. The synthesized compounds 3a-h and 4b, c, e, g exhibit anti-inflammatory activity.     

Synthesis, reactions and antimicrobial activity of new cyclopenta[e]thieno[2,3-b]pyridines and related heterocyclic systems

Reaction of the arylidene cyanothioacetamides 1a, b with cyclopentanone was proved to give a mixture of 4-aryl-3-cyanocyclopenta[b]pyridine-2(1H)-thiones 2a, b and the corresponding 7-arylidene derivatives 3a, b. Compounds 2a, b were reacted with ethyl chloroacetate or chloroacetamide to give the promising S-substituted thiopyridines 6a-d. On treatment of the latter compounds with sodium ethoxide in boiling ethanol, they underwent intramolecular Thorpe-Ziegler cyclization to yield the corresponding 3-amino-4-aryl-2-functionalized-cyclopenta[e]thieno[2,3-b]pyridines (7a-d). Most of these thienopyridines were reacted with a variety of reagents to produce other new cyclopentathienopyridines as well as numerous of their condensed heterocyclic derivatives. Some of the compounds synthesized were tested in vitro for their antibacterial and antifungal activity.     

Pharmacokinetic behaviour in polymorphonuclear leucocytes of N,N-dimethylcarbamoylmethyl α,2-dimethyl-5H-[1]benzopyrano[2,3-b]-pyridine-7-acetate (Y-23023), a new prodrug type of antiinflammatory agent,and indomethacin after oral administrations in rats

Abstract— N,N-Dimethylcarbamoylmethyl α,2-dimethyl-5H-[1]-benzopyrano[2,3-b]pyridine-7-acetate (Y-23023) is a prodrug developed as a new non-steroidal anti-inflammatory drug (NSAID). Y-23023 is rapidly hydrolysed to an active metabolite, α,2-dimethyl-5H-[1]benzopyrano[2,3-b]pyridine-7-acetic acid (M₁) following its absorption and then exhibits a strong anti-inflammatory activity. We have examined the pharmacokinetic behaviour in polymorphonuclear leucocytes (PMNs) of M₁ and of indomethacin after oral administration to rats of Y-23023 and indomethacin, respectively. Y-23023 was rapidly absorbed, producing a mean C_max (1·13 μg mL^?1) of M₁ after 1 h in plasma. Indomethacin was less rapidly absorbed, producing a mean C_max (3·38 μg mL^?1) after 3 h in plasma. The mean AUC of M₁ and indomethacin in plasma were 5·45 μg h mL^?1 and 22·49 μg h mL^?1, respectively. The mean t_max, C_max and AUC of M1 in PMNs were 1 h, 11·1 ng (41 pmol)/10⁸ cells and 58·6 ng (164 pmol) h/10⁸ cells, respectively. The same parameters for indomethacin in the PMNs were 3 h, 15·4 ng (57 pmol)/10⁸ cells and 95·2 ng (266 pmol) h/10⁸ cells, respectively. The PMNs/plasma ratio of M₁ was about 2·8 times that of indomethacin. These results indicate that the association of M₁, an active metabolite of Y-23023, from blood to the PMNs is greater than that of indomethacin.     

Synthesis and inotropic activity of pyrazolo[4,3-c]pyridine-4-ones and related compounds.

Two series of 3,6-dimethyl-1-phenyl-1H-pyrazolo[4,3-c] pyridine-4-ones (5-9) and 3,6-dimethyl-1-phenyl-1H-pyrazolo[4,3-c] pyridine-4-thiones (11-13) were prepared from dehydroacetic acid as starting material and evaluated for positive inotropic activity in vitro. Moreover, the activity of the synthesized compounds was compared with that of mirlinone as a reference. Among these compounds, the positive inotropic activity of 8a, 11a, and 12 were approximately 1.24, 1.77, and 1.11 times more potent, respectively, than that of mirlinone.     

Synthesis and tuberculostatic activity of some derivatives of imidazo [4, 5-b]pyridine-1-carboxylic acid

Imidazo [4,5-b] pyridine-2-carboxylic acid 2, its methyl ester 5, amide 7, hydrazide 12, hydrazone 14, nitrile 16, thioamide 18, and amidoxime 20 were synthesized. By methylation of acid 2 with diazomethane N3-CH3 derivatives of the above mentioned compounds were obtained. The resulting compounds displayed low tuberculostatic activity.     

Synthesis and anti-inflammatory activity of 3,3a-dihydro-2H,9H-isoxazolo [3,2-b] [1,3]benzoxazin-9-ones and related compounds.

A series of 3,3a-dihydro-2H,9H-isoxazolo[3,2-b]-[1,3]benzoxazin-9-ones was synthesized and evaluated for anti-inflammatory, antipyretic and analgesic activity. Since many of these compounds exhibited promising activity, particularly in the anti-inflammatory tests, a number of homologous 2,3,4,4a-tetrahydro-10H-1,2-oxazino[3,2-b]-[1,3]benzoxazin-10-ones and one 3,4,5,5a-tetrahydro-2H, 11H,-1,2-oxazepino [3,2-b][1,3]benzoxazin-11-one, the 9-chloro analog, were also prepared and evaluated. The expanded ring members were generally less active than the tricyclic compounds containing the isoxazolidine ring.     

2,3-Dihydro-9H-isoxazolo[3,2-b]quinazolin-9-ones and 3,4-dihydro-(1,2)-oxazino [3,2-b]quinazolin-10(2H)-ones.

Two series of compounds, 2,3-dihydro-9H-isoxazolo[3,2-b]quinazolin-9-ones and 3,4-dihydro-(1,2)-oxazino-[3,2-b]quinazolin-10(2H)-ones, were synthesized and evaluated for anti-inflammatory, antipyretic and analgesic activity. The isoxazolo compounds were generally more active than their oxazino homologs. Three compounds, i.e., 2,3-dihydro-9H-isoxazolo [3,2-b]quinazolin-9-one (W-2429) and its 2- and 3-methyl congeners, were the most active of all compounds tested in this study. On the basis of the biological results herein reported, W-2429 is considerably more effective than acetylsalicylic acid in inhibiting carrageenan-induced edema and in reducing brewer's yeast-induced fever in rats. Also, it was found to be more potent than propoxyphene hydrochloride in the Randall-Selitto test for analgesic activity.     

2H,5H-[1]benzothiopyrano [4,3-b]pyran derivatives with platelet antiaggregating activity

The synthesis of some N,N-disubstituted 4-amino-3-phenyl-2H,5H-[1]benzothiopyrano [4,3-b]pyran-2-ones by reaction of phenylchloroketene with a series of N,N-disubstituted 3-aminomethylene-2,3-dihydro-4H-1-benzothiopyran-4-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. Some of these compounds showed a strong platelet antiaggregating activity in vitro, superior to that of acetylsalicylic acid.     

New isoxazol /5,4-b/ pyridine-3-acetic acids]

We prepared two isoxazol [5,4-b] piridin-3-acetic acids by two different synthetic methods. 4,6-Dimethylisoxazole [5,4-b] pyridin-3-acetic acid was obtained by reaction with hydroxylamine of 4-hydroxy-5,7-dimethyl-2H-pyrano [2,3-b]pyridin-2-one, which was in turn prepared starting from 2-hydroxy-3-acetyl-4,6-dimethylpyridine. Isoxazolo [5,4-b] pyridine-3-acetic acid was obtained starting from 3-methyl-5-aminoisoxazole and has shown interesting auxin activity.     

1,3-Dihydro-2H-imidazo[4,5-b]quinolin-2-ones--inhibitors of blood platelet cAMP phosphodiesterase and induced aggregation.

A series of 1,3-dihydro-2H-imidazo[4,5-b]quinolin-2-one derivatives was synthesized and evaluated as inhibitors of cAMP hydrolysis by a crude human platelet phosphodiesterase preparation and as inhibitors of ADP- and collagen-induced aggregation of rabbit blood platelets. The parent structure 7a, demonstrated potent inhibitory activity that was enhanced by the introduction of alkyl, alkoxy, or halogen substituents at the 5-, 6-, 7-, and 8-positions. Methylation at N-1 or N-3 produced weaker inhibitors of cAMP PDE and platelet aggregation. 1,3,9,9a-Tetrahydro-2H-imidazo[4,5-b]quinolin-2-ones (6) were found to be equipotent with their fully oxidized congeners (7). On the basis of platelet inhibitory properties in vitro, efficacy at preventing thrombus formation in animal models of thrombosis, and a favorable hemodynamic profile, 1,3-dihydro-7,8-dimethyl-2H- imidazo[4,5-b]quinolin-2-one (7o, BMY 20844) was selected for advancement into toxicological evaluation and clinical trial. An efficient synthesis of 7o is described.     

Anti-inflammatory and analgesic activities of some newly synthesized pyridinedicarbonitrile and benzopyranopyridine derivatives

In continuation of our search for new substituted pyridine based anti-inflammatories, reaction of 1-(2-thienyl or furanyl)-3-(2-hydroxyphenyl)-2-propen-1-ones (1) with malononitrile in alcoholic KOH solution afforded a mixture of 4-alkoxy-2-(2-thienyl or furanyl)-5H-[1]benzopyrano[3,4-c]pyridine-5-ones (2) and 2-alkoxy-4-amino-6- (2-thienyl or furanyl)-3,5-pyridinedicarbonitriles (3). Some of the synthesized compounds were evaluated for their anti-inflammatory and analgesic activities compared to diclofenac potassium as positive control. Detailed synthesis, spectroscopic and toxicity data are reported.     

Dissolution properties and bioavailability of ground mixture of N,N-dimethylcarbamoylmethyl alpha, 2-dimethyl-5H-[1]benzopyrano[2,3-b]-pyridine-7-acetate with various pharmaceutical ingredients

Ground mixture of N,N-dimethylcarbamoylmethyl alpha, 2-dimethyl-5H-[1]benzopyrano-[2,3-b]pyridine-7-acetate (1) with various pharmaceutical ingredients were prepared in order to investigate their dissolution behaviors and bioavailability. Taking into account the weakly basic property of 1, the dissolution rate was determined in the 2nd fluid (pH 6.8) of disintegration test, JP XI. Dissolution rates of the ground mixtures (1 : 1, w/w) of 1 with hydroxypropylcellulose-L (HPC-L), low substituted hydroxypropylcellulose (L-HPC) or lactose respectively, showed a significant increase compared with compound 1 alone. Three kinds of experimental fine granules were prepared; type A: produced from ground mixture of 1, HPC-L, L-HPC and lactose; type B: produced from physical mixture having the same composition as type A; type C: produced 1, L-HPC and lactose. In these fine granules, only type A exhibited pH-independent dissolution profiles. Bioavailability study was carried out in beagle dogs whose gastric acidity was controlled in advance to low levels by administration of omeprazole. The test was conducted in a cross over design. Reflecting their dissolution characteristics, type A granules showed better bioavailability than the others. These results suggest that grinding is useful for the improvement of the dissolution property and bioavailability of 1, a weakly basic compound.     

Studies on 1,2,3-triazoles. 13. (Piperazinylalkoxy) [1]benzopyrano[2,3-d]-1,2,3-triazol-9(1H)-ones with combined H1-antihistamine and mast cell stabilizing properties

Several N-benzylpiperazino derivatives of [1]benzopyrano[2,3-d]-1,2,3-triazol-9(1H)-one and its 5-methyl homologue have been prepared and evaluated for H1-antihistamine activity on guinea pig ileum. The most potent compounds were also evaluated for their ability to stabilize mast cells in the rat passive peritoneal anaphylaxis (PPA) system and were shown to inhibit histamine release at concentrations below those required to inhibit extravasation, suggesting that this might be relevant to their antianaphylactic activity in this system. The compound tested with the most potent H1-antihistamine activity was 6-[3-[4-(4-chlorobenzyl)-1-piperazinyl]propoxy][1]benzopyrano[2,3- d]-1,2,3-triazol-9(1H)-one, 28, which had a pA2 of 9.1 against histamine on guinea pig ileum, comparable to that of mepyramine, and inhibited histamine release in the rat PPA system with an IC50 value of 5.4 X 10(-6) M.