Synthesis and antiproliferative activity in vitro of new pyrido[1,4-b]diazepine derivatives and imidazo[4,5-b]pyridine

A novel series of esters 8-10 and hydrazones 4-6 was synthesized from 4-aryl-2-phenacylidene-1,3,4,5-tetrahydropyrido[2,3-b][1,4]diazepine (1-3). Subsequent treatment of hydrazone 4 with p-chlorbenzaldehyde furnished azine 7. Long-standing heating of ester 8 with hydrazine hydrate afforded 3-[1-(p-chlorophenylene)-2-(5-phenyl-1H-pyrazol-3-yl)-ethyl]-1,3-dihydroimidazo[4,5-b]pyridin-2-one (11). The structures of 4-6 and 8-10 were identified by the results of elemental analysis and their IR, 1H-NMR and MS spectra. Additionally, the structure of 11 was confirmed by X-ray diffraction method. Compounds 8-10 and 11 were examined for their antiproliferative activity in vitro against the cells of 5 human cancer cell lines, using SRB or MTT technique. Among tested compounds, only 11 revealed cytotoxic activity in vitro against all cell lines applied with ID50 (inhibitory dose 50%) values lower than 4 microg/mL, which is an international activity criterion for synthetic compounds. All compounds inhibit the proliferation of HL-60 human promyelocytic leukemia cell line.     

Design and synthesis of highly potent benzodiazepine gamma-secretase inhibitors: preparation of (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4- hydroxy-N-((3S)-1-methyl-2-oxo-5- phenyl-2,3-dihydro-1H-benzo[e][1,4]-diazepin-3-yl)butyramide by use of an asymmetric Ireland-Claisen rearrangement

Novel benzodiazepine-containing gamma-secretase inhibitors for potential use in Alzheimer's disease have been designed that incorporate a substituted hydrocinnamide C-3 side chain. A syn combination of alpha-alkyl or aryl and beta-hydroxy or hydroxymethyl substituents was shown to give highly potent compounds. In particular, (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4-hydroxy-N-((3S)-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)butyramide (34) demonstrated excellent in vitro potency (IC(50) = 0.06 nM). 34 could also be selectively methylated to give [(3)H]-28, which is of use in radioligand binding assays.     

Design and synthesis of a potent and selective peptidomimetic inhibitor of caspase-3

In this paper we report the synthesis and characterization of a novel potent and selective inhibitor of caspase-3, a member of the caspase family of cysteine proteases which plays an important role in many human disorders. This molecule represents 3(S)-acetylamino-N-[1-[(((3S)-2-hydroxy-5-oxo-tetrahydrofuran-3-yl)carbamoyl)methyl]-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl]succinamic acid, a monocyclic conformationally constrained form of the tetrapeptide Ac-DEVD-H, in which a 1,4-benzodiazepine nucleus is introduced internally to the peptidic sequence.     

Synthesis of pyrazolo[3,4-e][1,4]diazepine-4,7-diones with central nervous system activity

The synthesis of 1-phenyl-5,8-dimethyl-1,4,5,6,7,8-hexahydro-pyrazolo[3,4-e][1,4] diazepin-4,7-dione and of 1-phenyl-3,5,8-trimethyl-1,4,5,6,7,8-hexahydro-pyrazolo[3,4-e] [1,4]diazepin-4,7-dione is described. These compounds exhibit activity on CNS in animals.     

The Biotransformation of 8-Chloro-6-phenyl-4H-s-triazolo[4, 3-a][1,4] benzodiazepine (D-40TA), a New Central Depressant,in Man,Dog and Rat

1. Metabolic studies of 8-chloro-6-phenyl-4H-^s-triazolo [4,3-a] [1,4] benzodiazepine (D—40TA) in man, dog and rat led to identification of the following metabolites: six hydroxylation products; 8-chloro-2,4-dihydro-6-phenyl-1H-s-triazolo[4,3-a] [1,4]benzodiazepin-1-one (I), 8-chloro-6-(4-hydroxyphenyl)-4H-s -triazolo[4,3-a][1,4]benzodiazepine (II), 8-chloro-6- (3-hydroxyphenyl)-4H-s-triazolo[4,3-a] [1,4] benzodiazepine (III), 8-chloro-4-hydroxy-6-phenyl-4H-s- triazolo[4,3-a][1,4]benzodiazepine (IV), 8-chloro-2,4-dihydro-6- (4-hydroxy-phenyl)-1H-s-triazolo[4,3-a] [1,4] benzodiazepin-1-one (V) and 8-chloro-2,4-dihydro-6-(3-hydroxyphenyl)- 1H-s- triazolo[4,3-a][1,4]benzodiazepin-1-one (VI); five ring-opened metabolites; 5-chloro-2-(4H-1,2,4-triazol-4-yl) -benzophenone (VII), 5-chloro-2- (2,3-dihydro-3-oxo- 4H -1,2,4- triazol-4-yl)benzophenone (VIII), 5-chloro-2- (2,3-dihydro-3-oxo-4H - 1,2,4-triazol-4-yl)-2-hydroxybenzophenone (IX), 5-chloro-2- (2,3-dihydro-3-oxo-4H-1,2,4-triazol-4-yl)-4'-hydroxybenzophenone (X) and 5-chloro-2-(3,5-dioxo-2,3,4,5-tetrahydro-1H-1,2,4-triazol-4-yl) benzophenone(XI).

2. In man, metabolites I, IV, VII and VIII are present as the free form in the urine, and I, II, IV and VIII are present as conjugates. In the dog, all the metabolites are present. The rat transforms the compound mainly to metabolites I, II, IV and V. None of the ring-opened metabolites are observed in the rat.     

Synthesis and interaction of 5-(substituted-phenyl)-3-methyl-6,7-dihydropyrazolo[4,3-e] [1,4]diazepin-8(7H)-ones with benzodiazepine receptors in rat cerebral cortex

On the basis of the anxiolytic property of ripazepam, 1-ethyl-4,6-dihydro-3- methyl-8-phenylpyrazolo[4,3-e][1,4]diazepin-5(1H)-one (1), a series of isomeric 5-(phenyl-substituted)pyrazolo[4,3-e][1,4] diazepin-8-ones 3a-f were prepared and tested for their ability to bind to the benzodiazepine receptor. All compounds 3a-f display affinities for the benzodiazepine receptor in the microM range of concentration; in particular 5-phenyl-3-methyl-6,7-dihydropyrazolo[4,3-e][1,4] diazepin-8(7H)-one (3a) is 2 orders of magnitude less potent in inhibiting [3H]flunitrazepam binding than diazepam and displays an affinity for the benzodiazepine receptor practically comparable to that of its structural isomer, ripazepam, and to that of chloriazepoxide.     

Central nervous system activity of a novel class of annelated 1,4-benzodiazepines, aminomethylene-2,4-dihydro-1H-imidazo[1,2-a][1,4]benzodiazepin-1-ones.

The synthesis and CNS activity of a noval class of annelated 1,4-benzodiazepines, the aminomethylene-2,4-dihydro-1H-imidazo[1,2-a][1,4]benzodiazepines, are described. An investigation of the structure--activity relationships in the series derived from 8-chloro-2,4-dihydro-2-dimethylaminomethylene-6-phenyl-1H-imidazo[1,2-a][1,4]-benzodiazepin-1-one (10) led to the synthesis of a group of compounds with potent minor tranquillizer activity.     

Photosynthese des 5-Phenyl-5,10-dihydro-dibenzo[b,e][1,4]-diazepin-11-ons aus 1.2-Diphenyl-indazolon

Photosynthesis of 5-Phenyl-5,10-dihydro-dibenzo[b,3][1,4]-diazepin-11-one from 1.2-Diphenyl-indazolone The UV irradiation of 1,2-diphenyl-indazolone in acetonitrile produced 5-phenyl-5,10-dihydrodibenzo[b,e][1,4] diazepin-11-one along with acridone and azobenzene. The structure of the first named product was confirmed by synthesis.     

New and mild method for the synthesis of alprazolam and diazepam and computational study of their binding mode to GABA<Subscript>A</Subscript> receptor

A new method for the synthesis of 8-chloro-1-methyl-6-phenyl-4H-benzo[f][1,2,4]triazolo[4,3-a][1,4]diazepine (alprazolam) and 7-chloro-1-methyl-5-phenyl-1H-benzo[e][1,4]diazepin-2(3H)-one (diazepam) from 2-amino-5-chloro benzophenone was described under mild conditions. Most of the synthetic steps were carried out under solvent-free conditions, and the products were obtained in high yield and purity. The products were characterized by comparison of physical properties with authentic samples and also by IR, ¹H NMR and ¹³C NMR. Three-dimensional (3D) model of GABA_A was constructed using X-ray crystal structure of homopentameric caenorhabditis elegans glutamate-gated chloride channel (GluCl) (3RHW) at 3.3 Å as the template based on sequence comparison and homology modeling method. The homology modeling and MD simulation studies predicted the 3D structure of receptor in a water environment. The resulted conformation of the receptor was used for docking of the alprazolam and diazepam. Docking studies indicated many important interactions of the drugs with the receptor. Furthermore, the complex of GABA with drugs was used in MD simulation to realize the conformation changes of the complex.     

奥氮平原料药中相关杂质的合成及结构鉴定

目的合成奥氮平原料药中的相关杂质并进行结构鉴定。方法分别以奥氮平的合成中间体4-氨基-2-甲基-10H-噻吩并[2,3-b][1,5]苯二氮杂艹卓盐酸盐和奥氮平为起始原料合成奥氮平的3个相关杂质:2-甲基-10H-噻吩并[2,3-b][1,5]苯二氮杂艹卓-4-(5H)-酮(1)、1-氯甲基-1-甲基-4-(2-甲基-10H-苯并[b]噻吩并[2,3-e][1,4]二氮杂艹卓-4-哌嗪基)-1-氯化物(2)和2-甲基-4-(4-甲基-1-哌嗪基)-10H-苯并[b]噻吩并[2,3-e][1,4]二氮杂艹卓4’-N-氧化物(3)。结果与结论合成并鉴定了奥氮平质量标准中提及的3种杂质,其结构经1H-NMR、13C-NMR谱及高分辨质谱确证;并且探讨了3种杂质可能的产生途径,以期为奥氮平的质量研究和相关杂质的控制提供帮助。     

Synthesis and antioxidant evaluation of some new 3-substituted coumarins

3-Acetylcoumarin (1) was utilized as a key intermediate for the synthesis of 2-aminothiazole derivative 3 via bromination of 1 to afford acetylbromide 2 followed by treatment with thiourea or via Biginelli reaction of 1. Treatment of 3 with 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde, 2-methyl-4H-benzo[d][1,3]oxazin-4-one, furo[3,4-b]pyrazine-5,7-dione or 2-methyl-5,6,7,8-tetrahydro-4H-benzothieno[2,3-d][1,3]oxazin-4-one afforded diazine derivatives 4-7. Also, pyridopyrimidine 8 was obtained via a one pot reaction of 6-aminothiouracil, p-chlorobenzaldehyde and 3-acetylcoumarin. Moreover, refluxing of 6-aminothiouracil with one equivalent amount of 2 afforded the thiazolopyrimidine 9, while the pyrrolothiazolopyrimidine 10 was revealed when two equivalent amounts of 2 was used. Furthermore, treatment of enamine 11 with 2-aminobenzothiazole or 6-aminothiouracil afforded the pyrimidine derivatives 12 and 13, respectively. Transamination of enamine 11 with m-anisidine followed by cyclization of the resulting enaminone 14 gave the desired quinoline 15. Also, treatment of 11 with thiophenol in dioxane gave the mercapto derivative 16. Moreover, coupling of 11 with 4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-3-yl-diazonium chloride, followed by complete cyclization of the resulting product afforded the pyridopyrazolothiazine 19 via the intermediate 18. Furthermore, the pyrazolopyrimidine 20 was revealed via a one pot condensation of 11, 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one and ammonium acetate. The thiadiazine derivatives 21-23 were obtained via treatment of 2 with the corresponding o-aminothiols. Desulphonation of 23 afforded the pyrazolotriazine 24. Finally, reaction of 2 with 2-hydroxybenzaldehyde gave benzofuran derivative 25. Representative compounds of the synthesized products were evaluated as antioxidant agents.     

Adenosine deaminase inhibitors. Synthesis and biological evaluation of (+/-)-3,6,7,8-tetrahydro-3-[(2-hydroxyethoxy)methyl]imidazo[4,5-d] [1,3]diazepin-8-ol and some selected C-5 homologues of pentostatin

The synthesis of several analogues of (8R)-3-(2-deoxy-beta-D-erythro- pentofuranosyl)-3,6,7,8-tetrahydroimidazo[4,5-d][1,3]diazepin-8-ol (pentostatin, 1a) is described. Ring closure of 2-amino-1-(5-amino-1H-imidazol-4-yl)ethanone dihydrochloride (3) with triethyl orthoacetate or triethyl orthopropionate gave the C-5 methyl and ethyl ketoaglycons, 6,7-dihydro-5-methylimidazo[4,5-d][1,3]diazepin-8(3H)-one (4b) and 5-ethyl-6,7-dihydroimidazo[4,5-d][1,3]diazepin-8(3H)-one (4c), respectively. Stannic chloride catalyzed condensation of the pertrimethylsilyl derivatives of 4b and 4c with a protected glycosyl halide afforded anomeric mixtures of ketonucleosides 3-(2-deoxy-3,5-di-O-p-toluoyl-beta- and -alpha-D-erythro-pentofuranosyl)-6,7-dihydro-5-methylimidazo[4,5-d] [1,3]diazepin-8(3H)-one (5b and 6b) and 3-(2-deoxy-3,5-di-O-p-toluoyl)-beta- and -alpha-D-erythro-pentofuranosyl)-5-ethyl-6,7-dihydroimidazo[4,5-d]- [1,3]diazepin-8(3H)-one (5c and 6c), respectively. Subsequent separation of the anomers, followed by deprotection and reduction of 5b, 6b, and 5c, afforded the respective 8R and 8S isomers. Stannic chloride catalyzed condensation of pertrimethylsilyl ketoaglycon 4a with 2-(chloromethoxy)-1-(p-toluoyloxy) ethane to give ketonucleoside 6,7-dihydro-3-[[2-(p-toluoyloxy)ethoxy] methyl]imidazo[4,5-d][1,3]diazepin-8(3H)-one (9a) was followed by deprotection to 6,7-dihydro-3[(2-hydroxyethoxy)methyl]imidazo[4,5-d][1,3] diazepin-8(3H)-one (9b) and then reduction to the racemic acyclic pentostatin analogue (+/-)-3,6,7,8-tetrahydro-3-[ (2-hydroxyethoxy)methyl]imidazo[4,5-d][1,3]diazepin-8-ol (2). Ki values for the in vitro adenosine deaminase (EC 3.5.4.4; type I; calf intestinal mucosa) inhibitory activities of 1b, 1c, and 2 were determined to be 1.6 X 10(-8), 1.5 X 10(-6), and 9.8 X 10(-8) M, respectively. When compounds 2 and 9b were tested in combination with vidarabine against herpes simplex virus, type 1, in an HEp-2 plaque reduction assay, only compound 2 was able to potentiate the antiviral activity of vidarabine.     

Synthesis and properties of amides of 1-benzyl-3-methyl- and 1-butyl-3-phenyl-7-methyl-4-oxo-2-thioxo (2,4-dioxo)-1,2,3,4-tetrahydropyrido-[2,3-d]pyrimidine-6-carboxy lic acids

Amides of 1-benzyl-3,7-dimethyl-4-oxo-2-thioxo-1,2,3,4- tetrahydropyrido[2,3]pyrimidine-6-carboxylic acid were obtained by the condensation of ammonia, primary and secondary cyclic amines with the corresponding acid chloride. As by - products amides of 1-benzyl-3,7-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrido[2,3-d]pyr imidine-6- carboxylic acid were isolated as a result of desulfuration. The same reaction performed with chloride of 1-butyl-7-methyl-3-phenyl-4-oxo-2-thioxo-1,2,3,4-tetrahydropyri do[2,3- d]pyrimidine-6-carboxylic acid gave mainly the corresponding 2,4-dioxo-amides.     

Effects of novel pyridothiazepines and pyridothiazines on contractility of isolated guinea-pig heart muscle and vascular smooth muscle preparations.

The effects of newly synthesized pyridothiazepines MM 4 (1-[N-[2-(3,4-dimethoxy-phenyl)ethyl]-N-methylaminoacetyl]-1,2,3,4 -tetrahydro-pyrido[2,3-b][1,4]thiazepine fumarate), MM 6 (1-[N-[2-(3,4-dimethoxyphenyl)-ethyl]-N-methylaminopropionyl]-1,2, 3,4-tetrahydro-pyrido[2,3-b][1,4]thiazepine fumarate) and the novel pyridothiazines MM 10 (2,3-dihydro-1-[N-[2-(3,4-dimethoxyphenyl)ethyl]-N-methylaminoacetyl+ ++]-1H-pyrido[2,3-b][1,4]thiazine fumarate) and MM 11 (2,3-dihydro-1-[N-[2-(3,4-dimethoxy-phenyl)ethyl]-N-methylaminopropio nyl]-1H-pyrido[2,3-b][1,4]thiazine fumarate) on the contractility of isolated papillary muscles and aortic preparations of guinea pigs were studied using isometric contraction force measurements. The EC50 values for the negative inotropic effect were 27 micromol/l (MM 4), 19 micromol/l (MM 6), 32 micromol/l (MM 10) and 24 micromol/l (MM 11). In K+-precontracted aortic rings ([K+]o 60 mmol/l), the compounds induced relaxation with EC50 values of 27 micromol/l (MM 4), 24 micromol/l (MM 6), 84 micromol/l (MM 10) and 68 micromol/l (MM 11). Pyridothiazepines as well as pyridothiazines (100 micromol/l) were able to depress norepinephrine bitartrate (NE 10 micromol/l)-induced contraction of aortic rings in a calcium-free solution. It was concluded that the investigated compounds exert calcium antagonistic properties in both cardiac and smooth muscle. This antagonistic effect might be due to the inhibition of transmembrane calcium influx and/or intracellular calcium release.     

Synthesis and pharmacological profile of non-peptide vasopressin antagonists

Recently we presented a series of 6-ethyl and 6-benzylthieno[2,3-b][1,4]thiazine derivatives with relaxing effects on vascular smooth muscle and terminal ileum. In this report the synthesis of further thieno[2,3-b][1,4]thiazine derivatives and related compounds with a thieno[2,3-b][1,4]thiazepine or thieno[3,2-b][1,4]thiazine ring system is described. The pharmacological effect of the agents was tested in isolated smooth (terminal ileum, pulmonary artery, aortic rings, myometrial strips) and heart (papillary muscle, spontaneously beating right atrium) muscle preparations of the guinea pig. Contractions were measured isometrically, and smooth muscle preparations were either precontracted with high K⁺ (60 or 90 mM KCl containing nutrient solution) or with agonists, while papillary muscles were electrically stimulated (1 Hz). The vasopressin antagonistic activity of the test compounds was tested in isolated papillary muscles in which the V_1A-receptor subtype is located. The biphasic response to vasopressin was antagonized, dependent on the chemical structure of the test compound. Thieno[3,2-b][1,4]thiazines were more potent than thieno[2,3-b][1,4]thiazine and thieno[2,3-b][1,4]thiazepine compounds. In addition, substitution of a methyl substituted terminal benzyl ring instead of a phenyl- or dichlorobenzoyl moiety attenuated the vasopressin antagonistic effect.     

Synthesis of potential anticancer agents. Pyrido[4,3-b][1,4]oxazines and pyrido[4,3-b][1,4]thiazines

Hydrolysis of the chloro group of ethyl (6-amino-4-chloro-5-nitropyridin-2-yl)carbamate (3) with formic acid gave the corresponding 4-hydroxypyridine 4. Catalytic hydrogenation of the nitro group of 4 gave the 5-amino-4-hydroxypyridine 5, which was reacted with alpha-halo ketones in acetic acid at room temperature to give a series of 3- and 2,3-substituted ethyl (5-amino-2H-pyrido[4,3-b][1,4]oxazin-7-yl)carbamates 8. Treatment of 8 with hot concentrated hydrochloric acid regenerated the pyridine synthon 5. In the reaction of 3 with thioacetate, the product underwent hydrolysis and air-oxidation to give the corresponding disulfide 6. Simultaneous reduction of both the nitro group and disulfide linkage of 6 gave the 5-amino-4-mercaptopyridine 7, which was reacted with alpha-halo ketones either in acetic acid at room temperature or in a mixture of ethanol and water at reflux to give a series of 3-, 2,3-, and 2,2,3-substituted ethyl (5-amino-2H-pyridol[4,3-b][1,4]thiazin-7-yl)carbamates 9. The effects of these pyridooxazines and pyridothiazines upon the proliferation and the mitotic index of cultured L1210 cells and upon the survival of mice bearing P388 leukemia were determined.     

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).     

Synthesis and antioxidant evaluation of some new pyrazolopyridine derivatives

4,6-Dimethyl-1H-pyrazolo[3,4-b]pyridine-3-amine (1) was used as a key intermediate for the synthesis of imidazolopyrazole derivatives 7-11 upon interaction with 3-(2-bromoacetyl)-2H-chromen-2-one (2), 2-(benzothiazol-2-yl)-4-chloro-3-oxobutanenitrile (3), 2,3-dibromonaphthalene-1,4-dione (4), naphtha[2,3-b]oxirene-2,7-dione (5), 2,5-dichloro-3,6-dihydroxyhexa-2,5-diene-1,4-dione (6), respectively. Acetylation of 11 afforded the bis-acetyl 12. Also, the imidazolopyrimidine 15 was prepared via treatment of 1 with sodium 3,4-dioxo-3,4-dihydronaphthalene-1-sulfonate (13) in DMF followed by cyclization of the bis-pyrazolopyrimidine 14 with glacial acetic acid. On the other hand, compound 1 was reacted with (E)-1-(4-methoxyphenyl)-5-(piperidin-1-yl)pent-1-en-3-one hydrochloride (16), 2-hydroxy-3-((piperidin-1-yl)-methyl)-naphthalene-1,4-dione (17), 2-styryl-2H-indene-1,3-dione (18), enaminone 22, chloroquinoline-3-carbaldehyde 27a, chloroquinoline-(6-methyl)-3-carbaldehyde 27b and 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (28) to afford pyrazolo[3,4-a]pyrimidines 19-21, 23, 29a, 29b and 30, respectively. Also, the pyrazolopyrimidinone 33 was obtained via treatment of 1 with 1-cyanoacetyl-3,5-dimethylpyrazole (31) followed by cyclization of the formed intermediate 32 with glacial acetic acid. Finally, treatment of 1 with o-terephthalaldehyde in glacial acetic acid afforded diazepine 34. The newly synthesized compounds were screened for their antioxidant properties in which some of them exhibited promising activities. Compounds 1, 14, 15, 23, 26, 29a, 30 and 32 have the ability to protect DNA from the damage induced by bleomycin.