Chemistry and pharmacology of pyrane derivatives. XVII. Synthesis of substituted 2-(dialkylamino)-3-formylchromones and their tricyclic derivatives

Substituted 2-(dialkylamino)-3-formylchromones (II) were obtained from the reaction of substituted 2-(dialkylamino)chromones (I) either with the N,N-dimethylformamide-POCl3 reagent [compounds (IIa-e)] or with dichloromethylmethylether in the presence of TiCl4 [compounds (IIf-i)]. By treating (IIa,f) with hydroxylamine the oximes (IIIa,f) were prepared, which in turn were converted into the nitriles (IVa,f) by treatment with acetic anhydride. Compound (IIa), selected for the smallest steric hindrance of the 2-dialkylamino substituent, by reaction with hydrazines afforded [1]benzopyrano [2,3-c]pyrazole derivatives (VI), whereas reaction of (IIa) with guanidine, benzamidine or S-methylisothiourea gave rise to the formation of 5H-[1]benzopyrano[2,3-d]pyrimidine derivatives (IX). Among the compounds tested for their antiallergic properties, (IIf) showed an appreciable activity, but also high toxicity.     

Synthesis of some new hydrazone derivatives as biologically active agents

A series of [4-(6H/bromo-4-oxo-2-phenyl-3(4H)-quinazolinyl)phenoxy]acetic acid (1,2-dihydro-1-H/methyl-2-oxo-3H-indol-3-ylidene)hydrazides (VII1-16) were synthesised by condensing 1-H/methyl-5-substituted indoline-2,3-diones with [4-(6H/bromo-4-oxo-2-phenyl-3(4H)-quinazolinyl) phenoxy]acetic acid hydrazides (IV1-2) which in turn were obtained by reacting ethyl [4-(6H/bromo-4-oxo-2-phenyl-3(4H)-quinazolinyl)phenoxy]acetates (III1-2) with hydrazine hydrate. All the synthesised compounds (VIII1-16) were screened for their antibacterial, acetylcholinesterase enzyme inhibitory and antiviral activities.     

Synthesis and evaluation of antileukemic activity of 5-thienyl- or 5-(2-furyl)-2,3-dihydro-6,7-bis(hydroxymethyl)-1H-pyrrolizine bis(alkylcarbamates) and derivatives

Treatment of N-(2-furoyl)proline or N-thenoylprolines and N-(2-thenoyl)thiazolidine-4-carboxylic acid with acetic anhydride and dimethyl acetylenedicarboxylate gave 5-substituted derivatives of dimethyl 2,3-dihydro-1H-pyrrolizine-6,7-dicarboxylate and derivatives of dimethyl 5-(2-thienyl)pyrrolo[1,2-c]thiazole. Reduction of 2 with lithium aluminum hydride gave the diols 3a, 3b, 3c and 3d. These diols yielded the corresponding diacetates 4 by treatment with acetic anhydride. The bis(methylcarbamates) 5a, 5b, 5c, and 5d and bis(isopropylcarbamates) 6b and 6c are obtained with the appropriate isocyanates. The 1-substituted pyrrolizines were synthesized, the 1-acetoxy compounds 7b and 7c further transformed into 1-hydroxy and 1-oxo analogues. The action of hydrochloric acid on 1-acetoxy derivatives gave 3H-pyrrolizines. Evaluation of antileukemic activity was investigated on the leukemia L1210 in vivo, on several bis(alkylcarbamates). The compounds 5c and 5d show good antileukemic activity comparable with the mitomycin.     

Synthesis of some 2-hydroxy-1-[(4-chloro-2-mercaptophenyl)sulfonyl]imidazole derivatives with potential anticancer activity

Several 2-(hydroxy or alkoxy)-1-[(4-chloro-5-R1-2-mercaptophenyl)sulfonyl]limidazoles [II-VI, IX-XI] and bis ?5-chloro-4-methyl-2-[(2-aryloxyimidazol-1-yl)sulfonyl]phenyl disulfides [XII-XV] were obtained by either the selective hydrolysis or alcoholysis of the appropriate 7-R1-8-chloroimidazo[1,2-b] [1,4,2]benzodithiazine 5,5-dioxides [Ia-d]. The structures of the products and their S-substituted derivatives [VII, VIII] were established on the basis of elemental analysis and spectral data (IR, 1H and 13C NMR). Preliminary screening data indicated that the investigated compounds [III, X, XII and XIII] exhibited weak [III, X], moderate [XII] or fairly high [XIII] activity against some human tumor cell lines (Table 1).     

Studies on annelated 1,4-benzothiazines and 1,5-benzothiazepines. II. Synthesis of new series of 1- or 2-substituted 4H-s-triazolo[3,4-c]-1,4-benzothiazines and related compounds with potential CNS activity

New series of 1- or 2-substituted 4H-s-triazolo[3,4-c]-1,4-benzothiazines have been prepared. The 1-substituted products were obtained starting from 3-hydrazino-2H-1,4-benzothiazine derivatives (III) by treatment with chloroacethyl chloride followed by cyclization of the resulting chloroacethylderivatives into the chloromethyltriazolobenzothiazines (IV a-e), which were then reacted with the appropriate amines to give the desired compounds (V a-n). Other 1-substituted compounds were prepared by ring closure of (III) with cyanogen bromide, affording 1-amino-4H-s-triazolo [3,4-c]-1,4-benzothiazines (XI a-e). The 2-substituted compounds (VIII) were prepared from 2,4-dihydro-1H-s-triazolo [3,4-c]-1,4-benzothiazin-1-ones (VII), synthesized from (I) by reaction with ethyl carbazate. The aminoalkyl side chain was introduced into (VII) in two steps: first by treatment with 1-bromo-3-chloropropane, then by refluxing the resulting product with the appropriate amine. Some 4H-tetrazolo[5,1-c]-1,4-benzothiazines (XII) were also synthesized from (III). Preliminary pharmacological data on the CNS activity of the synthesized tricyclic compounds are reported.     

Discovery of 2-(4-methylfuran-2(5H)-ylidene)malononitrile and thieno[3,2-b]thiophene-2-carboxylic acid derivatives as G protein-coupled receptor 35 (GPR35) agonists

Screening with dynamic mass redistribution (DMR) assays in a native cell line HT-29 led to identification of two novel series of chemical compounds, 2-(4-methylfuran-2(5H)-ylidene)malononitrile and thieno[3,2-b]thiophene-2-carboxylic acid derivatives, as GPR35 agonists. Of these, 2-(3-cyano-5-(3,4-dichlorophenyl)-4,5-dimethylfuran-2(5H)-ylidene)malononitrile (YE120) and 6-bromo-3-methylthieno[3,2-b]thiophene-2-carboxylic acid (YE210) were found to be the two most potent GPR35 agonists with an EC(50) of 32.5 ± 1.7 nM and 63.7 ± 4.1 nM, respectively. Both agonists exhibited better potency than that of zaprinast, a known GPR35 agonist. DMR antagonist assays, knockdown of GPR35 with interference RNA, receptor internalization assays, and Tango β-arrestin translocation assays confirmed that the agonist activity of these ligands is specific to GPR35. The present study provides novel chemical series as a starting point for further investigations of GPR35 biology and pharmacology.     

Synthesis and antimicrobial evaluation of new pyrano[4,3-b]pyran and Pyrano[3,2-c]chromene derivatives bearing a 2-thiophenoxyquinoline nucleus

A new series of pyrano[4,3-b]pyran 4a-i and pyrano[3,2-c]chromene 6a-r derivatives bearing a 2-thiophenoxyquinoline nucleus were synthesized by reaction of 2-(4-(un)-substituted thiophenoxy)quinoline-3-carbaldehydes 2a-i with 6-methyl-4-hydroxypyran-2-one 3 and 4-hydroxy-6-(un)-substituted-2H-chromen-2-one 5a-b respectively and malononitrile at room temperature in the presence of KOH as a basic catalyst. All the compounds were screened against three Gram-positive bacteria (Streptococcus pneumoniae, Bacillus subtilis, Clostridium tetani), three Gram-negative bacteria (Salmonella typhi, Escherichia coli, Vibrio cholerae) and two fungi (Candida albicans, Aspergillus fumigatus) using the broth microdilution MIC (minimum inhibitory concentration) method. Upon antimicrobial screening, it was observed that the majority of the compounds were found to be active against Bacillus subtilis, Clostridium tetani and Candida albicans as compared to standard drugs.     

抗心肌缺血药3-{4-[(2-羟基-3-烷氨基)丙氧基]苯基(苄基)}-取代4(3H)-喹唑酮的合成

In order to search for effective antimyocardial ischemic agents, fourteen new 3 4-[(3-alkylamino-2-hydroxy)propoxy] phenyl(benzyl)]-substituted 4(3H)-quin zolinones (Ⅱ) were synthesized. Substituted o-aminobenzoic acids used as the starting materials were allowed to react with acetic anhydride and then p-aminophenol (method A), or with N- (4- hydroxyphenyl)formamide (method B), or with thionyl chloride and then N - (4 - hydroxybenzyl) formamide (methode C) to form 3-[(4-hydroxyphenyl(benzyl)]-substituted 4(3H)-quinazolinones (Ⅲ). The intermediate Ⅲ reacted with epichiorohydrin to form the epoxides (Ⅳ). The reaction of Ⅳ with an excess of isopropylamine or tert-butylamine in boiling chloroform gave the desired products. Of all the compounds synthesized, Compounds Ⅱ_3～5 and Ⅱ₁₃ were found to increase the tolerance of mice to hypoxia. Further evaluation is in progress.     

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.     

Synthesis of novel substituted 7-(benzylideneamino)-4-methyl-2H-chromen-2-one derivatives as anti-inflammatory and analgesic agents

A series of novel Schiff' base-containing a 7-amino-4-methylcoumarin moiety have been synthesized III a-l, characterized by spectroscopic data and studied for their anti-inflammatory and analgesic activity. The results of the anti-inflammatory and analgesic activity evaluation of 7-(substituted benzylideneamino)-4-methyl-2H-chromen-2-one derivatives III a-l proved to be comparable or more potent with respect to the reference drugs. In particular, compounds 7-(4-chlorobenzylideneamino)-4-methyl-2H-chromen-2-one III f, 7-(2,4-dichlorobenzylideneamino)-4-methyl-2H-chromen-2-one III g and 7-(4-bromobenzylideneamino)-4-methyl-2H-chromen-2-one III h exhibited potent anti-inflammatory and analgesic activity.     

1,5-benzodiazepines. V. Synthesis of pyrazolo (3,4-b)(1,5)benzodiazepines and 5H-pyrimido(4,5-b)(1,5)benzodiazepines

The reaction of 4-(dialkylamino)-1,3-dihydro-2H-1,5-benzodiazepin-2-ones (I a-c) with N,N-dimethylformamide in the presence of phosphorus pentachloride at room temperature gave rise to the formation of 4-(dialkylamino)-3-[(dimethylamino)methylene]-1,3-dihydro-2H-1,5-benzodiazepin- 2-ones (IX a-c) which were useful starting materials to achieve the synthesis of tricyclic 1,5-benzodiazepine derivatives. Actually (IX a), selected for the smallest steric hindrance of the 4-dialkylamino substituent, by reaction with hydrazines afforded pyrazolo[3,4-b][1,5]benzodiazepine derivatives whereas reaction with guanidine or amidines gave 5H-pyrimido-[4,5-b][1,5]benzodiazepine derivatives. The structure of isomeric N-methyl-pyrazoles (X c) and (XI a) and of N-phenylpyrazole (X b) were elucidated by comparison with compounds prepared by unequivocal chemical methods. Pharmacological evaluation of some of the products showed only generic CNS depressant activity.     

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.     

Synthesis and evaluation of anti-inflammatory activity of some thiazolo[3,2-b]-1,2,4-triazole-5(6H)-ones and their Michael addition products

Thiazolo[3,2-b]-1,2,4-triazole-5(6H)-ones (4-10) were obtained in a one step synthesis by heating 3-aryl-5-mercapto-1,2,4-triazoles (3a-d) with chloroacetic acid and appropriate aromatic aldehyde in acetic acid and acetic anhydride in the presence of anhydrous NaOAc. Michael type addition of cyclic secondary amines (N-methylpiperazine, piperidine) to 4-10 gave 2-phenyl-6-(alpha-aminoarylmethyl)thiazolo[3,2-b]-1,2,4-triazole-5 -ols (4a-10b). The structures of the compounds were confirmed by spectral and elementary analysis. The compounds synthesized in previous and present studies were investigated for their anti-inflammatory activities.     

1,5-Benzodiazepines. X. Dialkylamino substituted 1,5-benzodiazepine and [1,2,4]triazolo [4,3-a][1,5] benzodiazepine derivatives with inhibitory activity on PAF-induced platelet aggregation.

Novel 4-(dialkylamino) substituted (4, 5 c, 8) and 2,4-bis(dialkylamino) substituted (6) 1,5-benzodiazepine derivatives were synthesized. Both these new compounds and the substituted 4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepine-5-amines 2 a-h, recently described by us, were tested in vitro for their inhibitory activity on the PAF-induced aggregation of human platelets. Actually, bicyclic compounds 4 d, 5 c and tricyclic compounds 2 g, h showed a significant activity: in all them the dialkylamino substituent was the 4-(ethoxycarbonyl)-1-piperazinyl group. On the contrary, compounds 4 d, 5 c, 2 g,h showed practically no inhibitory activity when platelet aggregation was induced by ADP, A23187, or collagen.     

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 and antimycobacterial activity of (3,4-diaryl-3H-thiazol-2-ylidene)-hydrazide derivatives

[5-(pyridin-2-yl)-1,3,4-thiadiazol-2-ylthio]acetic acid (3,4-diaryl-3H-thiazol-2-ylidene)-hydrazide derivatives were synthesized and tested for their in vitro antimycobacterial activity. Some compounds showed an interesting activity against a strain of Mycobacterium tuberculosis H(37)Rv and three clinical isolates of M. tuberculosis.     

Synthesis and evaluation of (Des-Asp1)angiotensin I as a precursor for (Des-Asp1)angiotensin II ("Angiotensin III").

The nonapeptide [des-Asp1]angiotensin I (IV), synthesized by Merrifield's solid-phase procedure, was tested as a possible substrate for the converting enzymes from porcine lung and plasma. IV, [des-Asp1]angiotensin II (III), [des-(Asp1,Arg2)]angiotensin II (V), [des-(Asp1,Arg2,Val3)]angiotensin II (VI), [Sar1,Ile8]angiotensin II (VII), and [des-Asp1,Ile8]angiotensin II (VIII) possessed 0.5, 20, 2, 0 less than 0.1, and less than 0.01% of the inotropic activity (rabbit atria), 1, 15, 5, 0, 3, and 0% secretory activity of the cat adrenal medulla, and 0.0, 150, 0.5, 3, and 10% of the adrenal steroidogenic activity of angiotensin II, respectively. When tested for their antagonistic activity in the above tissues, only VII and VIII were found to inhibit responses to angiotensin II. The pA2 values for VII and VIII were 8.31 and 10.0 in the adrenal cortex and 9.31 and 9.16 in the adrenal medulla, respectively. All these peptides were also tested as product inhibitors for the plasma and lung converting enzymes. With the plasma enzyme, the ID50 values were II, 1.6 X 10(-4) M; III, 5 X 10(-5) M; V, 1.2 X 10(-4) M; VI 5 X 10(-4) M; VII 5 X 10(-5) M; VIII, 5 X 10(-4) M. Thus, IV is a good substrate for converting enzymes from lung and plasma while all other compounds were inhibitors of these enzymes. The most potent inhibitors of converting enzyme were III followed by VII and VIII. With the exception of II and III, all the other analogs had very low intrinsic activities, per se. These results suggest (a) an alternate pathway for the formation of heptapeptide III, viz., by the action of converting enzyme on the nonapeptide IV, and (b) that III may also be acting as inhibitor of the converting enzyme by the feedback mechanism.     

Antimalarial activity of 2-(substituted amino)-4,6-bis(trichloromethyl)-1,3,5-triazines and N-(chlorophenyl)-N'-[4-(substituted amino)-6-(trichloromethyl)-1,3,5-triazin-2-yl]guanidines

A series of 2-[[(dialkylamino)alkyl]amino]-4,6-bis(trichloromethyl)-1,3,5-triazines (III) and N-(4-chlorophenyl)-N'-[4-[[(dialkylamino)alkyl]amino]-6- (trichloromethyl)-1,3,5-triazin-2-yl]guanidines (IV) were prepared from 2,4,6-tris(trichloromethyl)-1,3,5-triazine and 2-chloro-4,6-bis(trichloromethyl)-1,3,5-triazine. Compounds of type III showed modest antimalarial activity while XIa with the camoquin side chain was more potent. Analogues of type IV broadly exhibited modest antimalarial activity.     

Synthesis and molluscicidal activity of new cinnoline and pyrano [2,3-c]pyrazole derivatives

2-(3-Hydroxy-5,5-dimethylcyclohexylidene)malononitrile 5 undergoes an azo coupling reaction with aryldiazonium salts to afford 3-amino-2-aryl-6,6-dimethyl-8-oxo-2,6,7,8-tetrahydrocinnoline-4-carbonitriles 7. Upon reflux in acetic acid, these compounds were acetylated to give the cinnoline derivatives 9. The pyrazolones 10a, b react with 3-furfurylidene- and 3-thienylidene-malononitrile derivatives 11a, b to afford the pyrano[2,3-c]pyrazole derivatives 13a-d. These newly synthesized compounds show generally a moderate molluscicidal activity to Biomphalaria alexandrina snails.     

Novel 3,3a,4,5,6,7-hexahydroindazole and arylthiazolylpyrazoline derivatives as anti-inflammatory agents

A novel series of 7-benzylidene-3, 3a, 4, 5, 6, 7-hexahydro-3-phenyl-2H-indazole substituted at the 2-position were synthesized. The reaction of 2, 6-bis-benzylidenecyclohexanone (1) with thiosemicarbazide in the presence of NaOH afforded a mixture of the 3-H, 3a-H trans 2 and cis 2a diastereoisomers which have been separated by fractional recrystallization. Interaction of the first intermediate 2 with substituted phenacyl bromides, aromatic aldehydes and chloroacetic acid in presence of a mixture of acetic acid and acetic anhydride, and 2, 3-dichloroquinoxaline yielded the corresponding 7-benzylidene-3, 3a, 4, 5, 6, 7-hexahydro-3-phenyl-2H-indazole derivatives substituted at the 2-position with 4-aryl-2-thiazolyl 3a, b, 5-arylidene-4, 5-dihydro-4-oxo-2-thiazolyl 4a, b and thiazolo[4, 5-b]quinoxalin-2-yl 5, respectively. Moreover, the other intermediates 3, 5-diaryl-1-thiocarbamoyl-2-pyrazolines 7a-d were reacted with the previously-mentioned reagents and gave the corresponding 3, 5-diaryl-1-(4-aryl-2-thiazolyl)-2-pyrazolines 8a-h, 3, 5-diaryl-1-(5-arylidene-4, 5-dihydro-4-oxo-2-thiazolyl)-2-pyrazolines 9a-d and 3, 5-diaryl-1-(thiazolo[4, 5-b]quinoxalin-2-yl)-2-pyrazoline derivatives 10a, b, respectively. Some of the newly prepared compounds were subjected to evaluation for their anti-inflammatory activity. The structures of the new compounds were confirmed by elemental analyses as well as (1)H-NMR, IR, and MS data.