Chemistry of 1,2,3-thiadiazole. IV. Synthesis of [1]benzoxepino-[3,4-d][1,2,3]thiadiazole, [1]benzothiepino-[3,4-d][1,2,3]thiadiazole, [1]benzoxepino[4,3-d][1,2,3]thiadiazole, [1]benzoxepino[4,3-d]oxazole and [1]benzoxepino[4,3-d]oxazole. Four novel heterocycles

Starting from the readily available 4-bromomethy-5-carbethoxy 1,2,3-thiadiazole (V), 5-bromomethy-4-carbethoxy-1,2,3-thiadiazole (IX) and ethyl 2-aryl-5-bromomethyloxazole-4-carboxylate (XIV), 4,10-dihydro-10-oxo[1]benzoxepino[3,4-d][1,2,3]thiadiazole (Ia), 4,10-dihydro-10-oxo[1]benzothiepino[3,4-d][1,2,3]thiadiazole (Ib), 4,10-dihydro-4-oxo[1]benzothiepino[4,3-d] [1,2,3]thiazole (II), 2-aryl-4,10-dihydro-4-oxo[1]benzoxepino[4,3-d]oxazoles (XIXa-XIXc) and 2-aryl-4,10-dihydro-4-oxo[1]benzothiepino[4,3-d]oxazoles (XIXd-XIXf) were prepared.     

Polycyclic N-hetero compounds. XXXV. Syntheses and anti-platelet aggregation activity of 5,6-Dihydro-4H-benzo[3,4]cyclohept[1,2-e]imidazo[1,2-c]pyrimidines with an oxygen function at the 1-position

Various 6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-d][pyrimidines bearing amino acid group at the 4-position of the skeleton were synthesized by the reaction of 4-chloro-6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-d]-pyrimidine with some amino acid, which were cyclized to 5,6-dihydro-4H-benzo[3,4]cyclohept[1,2-e]imidazo-[1,2-c]pyrimidines, corresponding to B-homo-11,13,15-triazasteroids. Their inhibitory activities against platelet aggregation induced by collagen were also investigated.     

Synthesis of 1,6-dihydro-1,6-dihydroxybenzo[1,2-d:3,4-d′]bistriazole, 4- and 5-nitro-1,6-dihydro-1,6-dihydroxybenzo[1,2-d:3,4-d′]bistriazole and 4,7-dihydro-1,4,7-trihydroxy-1H-benzo-[1,2-d:3,4-d′:5,6-d″]tris[1,2,3]triazole

1,6-Dihydro-1,6-dihydroxybenzo[1,2-d:3,4-d′]bistriazole and 4- and 5-nitro-1,6-dihydro-1,6-dihydroxybenzo[1,2-d:3,4-d′]bistriazole were synthesized starting from 2,4-dinitrosore-sorcinol, whereas 4,7-dihydro-1,4,7-trihydroxy-1H-benzo[1,2-d:3,4-d′:5,6-d″]tris[1,2,3]-triazole was synthesized starting from phloroglucinol. The reaction of trinitrosophloroglucinol with hydrazine hydrate in acetic acid led to 2,4,6-tridiazocyclohexane-1,3,5-trione.     

Synthesis of two new heterocyclic ring systems: Benzo[3,4] cyclohepta[1,2-d]-pyrimidines and benzo[3,4]cyclohepta[2,1-d] pyrimidines

Three 2,4-diamino-l(), 11-dihydro-9H-benzo[3,4]cyclohepta[ 1,2-d]pyrimidines (6a-6c) representing the first examples of a new ring system were synthesized from 2-benzosuberones and cyanoguanidine. Similarly, 2,4-diamino-6,7-dihydro-5H-benzo[3,4]cyelohepta[2,1-d]pyrimidine ( 24 ) was prepared from 1-benzosuberone. The ultraviolet spectral properties of these compounds were examined with reference to those of the analogs in which the central ring is five- and six-mernbered.     

Synthèse et structure d'oxo-2 benzo-5,6 dihydro-3,4 oxathiazines-1,2,3

Reaction of thionyl chloride with various 1,3-aminophenols gives two series of cyclic sulfinamates. The structure of these 3,4-dihydro-2H-benzo[2][1,2,3]oxathiazines is shown by nmr and also for the 3 series by equilibration of the diastereoisomers.     

Synthesis of 2-Aryl-4-(R-sulfanylmethyl)-3-methyl-6,7-dihydro-2<Emphasis Type="Italic">H</Emphasis>-pyrazolo[3,4-<Emphasis Type="Italic">d</Emphasis>]pyridazin-7-ones

Bromination of ethyl 1-aryl-4-acetyl-5-methyl-1H-pyrazole-3-carboxylates gave ethyl 1-aryl-4-(bromoacetyl)-5-methyl-1H-pyrazol-3-carboxylates which were used to alkylate benzenethiol and heterocyclic thiones at the sulfur atom. Reactions of the resulting S-alkylation products with hydrazine or methylhydrazine involved closure of pyridazine ring to afford 2-aryl-3-methyl-4-[phenyl(or hetaryl)sulfanylmethyl]-6,7-dihydro-2H-pyrazolo[3,4-d]pyridazin-7-ones.     

Conversion of 3‐amino‐4‐arylamino‐1H‐isochromen‐1‐ones to 1‐arylisochromeno[3,4‐d][1,2,3]triazol‐5(1H)‐ones: synthesis,spectroscopic characterization and the structures of four products and one ring‐opened derivative

An efficient synthesis of 1‐arylisochromeno[3,4‐d][1,2,3]triazol‐5(1H)‐ones, involving the diazotization of 3‐amino‐4‐arylamino‐1H‐isochromen‐1‐ones in weakly acidic solution, has been developed and the spectroscopic characterization and crystal structures of four examples are reported. The molecules of 1‐phenylisochromeno[3,4‐d][1,2,3]triazol‐5(1H)‐one, C₁₅H₉N₃O₂, (I), are linked into sheets by a combination of C—H…N and C—H…O hydrogen bonds, while the structures of 1‐(2‐methylphenyl)isochromeno[3,4‐d][1,2,3]triazol‐5(1H)‐one, C₁₆H₁₁N₃O₂, (II), and 1‐(3‐chlorophenyl)isochromeno[3,4‐d][1,2,3]triazol‐5(1H)‐one, C₁₅H₈ClN₃O₂, (III), each contain just one hydrogen bond which links the molecules into simple chains, which are further linked into sheets by π‐stacking interactions in (II) but not in (III). In the structure of 1‐(4‐chlorophenyl)isochromeno[3,4‐d][1,2,3]triazol‐5(1H)‐one, (IV), isomeric with (III), a combination of C—H…O and C—H…π(arene) hydrogen bonds links the molecules into sheets. When compound (II) was exposed to a strong acid in methanol, quantitative conversion occurred to give the ring‐opened transesterification product methyl 2‐[4‐hydroxy‐1‐(2‐methylphenyl)‐1H‐1,2,3‐triazol‐5‐yl]benzoate, C₁₇H₁₅N₃O₃, (V), where the molecules are linked by paired O—H…O hydrogen bonds to form centrosymmetric dimers.     

Heterocyclic Rearrangement of 4,5,6,7-Tetrahydro-6,6-dimethyl-benzo[c][1,2,5]oxadiazol-4-one (Z)-Arylhydrazones into Corresponding 2-Aryl-4,5,6,7-tetrahydro-2H-benzo[d][1,2,3]triazol-4-one Oximes

The thermal base-catalysed and photochemical transformation (Boulton-Katritzky rearrangement) of the title tetrahydrobenzo[c][1,2,5]oxadiazoles to tetrahydro-2H-benzo[d][1,2,3]triazoles is studied. Attempts to induce analogous rearrangement in tetrahydro-2H-benzo[d][1,2,3]triazol-4-one arylhydrazones or oximes failed. Some CNDO/2 calculation are also carried out.     

Reaction of dichloroketene and sulfene with N,N-disubstituted 6-amino-methylene-b,7,8,9 -tetrahydro-5H-benzocyclohepten-5-ones. Synthesis of 6-(2,2-Dichloroethylidene)-b,7,8,9-tetrahydro-5H-benzocyclohepten-5-one and of 5H-benzo[3,4]cyclohepta[2,l-b]pyran and 5H-Benzo[3,4]cyclo-hepta[1,2-e]-1,2-oxathiin derivatives

The 1,4-cycloaddition of dichloroketene to N,N-disubstituted 6-aminomethylene-b,7,8,9-tetra-hydro-5H-benzocyclohepten-5-ones afforded N,N-disubstituted 4-amino-3,3-dichloro-3,4,6,7-tetrahydro-5H-benzo[3,4]cyclohepta[2,l-b]pyran-2-ones only in the case of aromatic or strong hindering aliphatic N-substitution. The adducts gave N,N-disubstituted 4-amino-3-chloro-b,7-dihydro-5H-benzo[3,4]cyclohepta[2,l-b]pyran-2-ones by dehydrochlorination with collidine. Upon chromatography on neutral alumina, two products were instead isolated in the case of usual aliphatic N-substitution (diethylamine, piperidine), namely 6-(2,2-dichloroethylidene)-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one and the dehydrochlorinated 2-pyrone; this latter was the sole product in the case of pyrrolidine substitution. The 1,4-cycloaddition of sulfene occurred readily to give N,N-disubstituted 4-amino-3,4,6,7-tetrahydro-5H-benzo[3,4]cyclohepta-[1,2-e]-1,2-oxathiin 2,2-dioxidesin the case of both aliphatic and partially aromatic N-substitution.     

7-(2-fluorobenzyl)-4-(substituted)-7-H-imidazo[4,5-d −1,2,3-triazines and −7H-pyrazolo[3,4-d]-1,2,3-triazines. Synthesis and anticonvulsant activity

The imidazo[4,5-d]-1,2,3-triazine and pyrazolo[3,4-d]-1,2,3-triazine analogues of the potent anticonvul-sant purine, BW 78U79 (9-(2-fluorobenzyl)-6-methylamino-9H-purine, 1 ), were synthesized and tested for anticonvulsant activity. The imidazo[4,5-d]-1,2,3-triazines 11–13 were prepared in four steps from 5-aminoimidazole-4-carboxamide (2) and the pyrazolo[3,4-d]-1,2,3-triazines 18–21 were synthesized starting with 5-amino-1-(2-fluorobenzyl)pyrazole-4-carbonitrile (14) . The intermediate 1,2,3-triazin-4-ones 6 and 16 were converted to the 4-substituted targets via the 4-(4-dimethylaminopyridinium) salts 10 and 17 . Imidazotriazine 11 had potent anticonvulsant activity against maximal electroshock-induced seizures, but its propensity to cause emesis precluded further development.     

Synthesis of new fluorine-containing pyrazolo[3,4-<Emphasis Type="Italic">b</Emphasis>]pyridinones as promising drug precursors

Methods for the synthesis of 4-R-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones (R = CF₂SAr and 4-CFHSAr) were developed. The derivatives with R = CF₂SAr were obtained by both heterocyclization of 1-substituted 5-aminopyrazoles with ethyl 4,4-difluoro-3-oxo-4-phenylsulfanylbutanoate and replacement of the Br atom in 4-bromodifluoromethyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones by sodium arenethiolates. The fragment 4-CF-HSAr was introduced by replacement of the Cl atom in 4-chlorofluoromethyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones by sodium arenethiolates. Oxidation of 4-CF₂SPh-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones gave the corresponding sulfoxides; their structures were confirmed by X-ray diffraction data.     

Synthesis of pyrazolo[4,3-<Emphasis Type="Italic">e</Emphasis>][1,2,4]triazolo[4,3-<Emphasis Type="Italic">c</Emphasis>]pyrimidines

Starting from 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones, a synthesis pathway to the tricyclic pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines is described. Reaction of 1,5-dihydro-4H-pyrazolo[3,4-d] pyrimidin-4-ones with phosphoryl chloride afforded the corresponding 4-chloro-1H-pyrazolo[3,4-d]pyrimidines. Treatment of these compounds with hydrazine hydrate at reflux temperature gave the hydrazino derivatives, which were subsequently cyclized to the titled compounds on heating with orthoesters in ethanol. Correspondence: Abolghasem Davoodnia, Department of Chemistry, School of Sciences, Islamic Azad University, Mashhad Branch, Mashhad 91735-413, Iran.     

New functionalization opportunities for <Emphasis Type="Italic">peri</Emphasis>-hydroxynaphthoyl and <Emphasis Type="Italic">peri</Emphasis>-fused heterocyclic compounds

A capability was studied of hydrogenated α-pyrone heterocycle in 7-methoxy-4-(4-methoxy-phenyl)-3,4-dihydro-2H-benzo[h]chromen-2-one to undergo aminolysis under the treatment with hydrazine hydrate, primary and secondary aliphatic and aromatic amines. A new approach was developed to the preparation of perihydroxyketone of naphthalene series containing a specific functional substituent in the ortho-position with respect to hydroxy group. The effect was revealed of an acetyl group in the position 9 of 7-methoxy-4-(4-methoxyphenyl)-3,4-dihydro-2H-benzo[h]chromen-2-one on the reaction of this compound with aliphatic amines and hydrazine hydrate. 9-Methoxy-1-(4-methoxyphenyl)-6-methyl-3H-benzo[de]pyrido[3,2,1-if]cinnolin-3-one [9-methyl-6-methoxy-3-(4-methoxyphenyl)-10,10a-diazapyren-1-one] was obtained, a new bis-peri-fused heteroaromatic system.     

Synthesis and structural assignment of 5,6-dihydro-8-hydroxy-9-methoxy-1H,7H-benzo[ij] quinolizine-1,7-dione

The compound 5,6-dihydro-8-hydroxy-9-methoxy-1H,7H-benzo[ij]quinolizine-1,7-dione ( 4a ) was synthesized from 3-(1,4-dihydro-6,7-dimethoxy-4-oxo-1-quinolyl)propionic acid ( 3a , free base), involving spontaneous demethylation with ring closure. The structural assignment of 4a was based on an analogous, unequivocal synthesis of 5,6-dihydro-9-ethoxy-8-hydroxy-1H,7H-benzo[ij]quinolizine-1,7-dione hydrochloride ( 4b ).     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones. XIII. Synthesis of 2H-pyrano[3,2-d]-1-benzoxepin derivatives

Cycloaddition of dichloroketone to N,N-disubstituted (E)-4-aminomethylene-3,4-dihydro-1-benzoxepin-5(2H)-ones gave N,N-disubstituted 4-amino-3,3-dichloro-3,4,5,6-tetrahydro-2H-pyrano[3,2-d]-1-benzoxepin-2-ones II, which are derivatives of the new heterocyclic system 2H-pyrano[3,2-d]-1-benzoxepin. Dehydrochlorination with triethylamine of II afforded N,N-disubstituted 4-amino-3-chloro-5,6-dihydro-2H-pyrano-[3,2-d]-1-benzoxepin-2-ones III in good to moderate yields. In the triethylamine treatment of IIh (NR₂ = diphenylamino), 3-chloro-5,6-dihydro-2H-pyrano[3,2-d]-1-benzoxepin-2-one was isolated in low yield near to IIIh, whereas IIc (NR² = diisopropylamino) gave in low yield 4-diisopropylamino-5,6-dihydro-2H-pyrano(3,2-d)-1-benzoxepin-2-one.     

Polycyclic N-hetero compounds. XXXIII. Syntheses of 4-substituted 6,7-dihydro-5H-benzo[6,7]-cyclohepta[1,2-d]pyrimidines and their inhibitory activities on platelet aggregation and on reserpine-induced hypothermia

Various 4-substituted 6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-d]pyrimidines were synthesized by the reaction of 4-chloro-6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-d]pyrimidine with amines. Their inhibitory activities against collagen-induced platelet aggregation and also against reserpine-induced hypothermia in mice were investigated.     

Polycyclic N-heterocyclic compounds. XLV. Synthesis of 4-substituted 5,6-dihydrobenzo[h]quinazolines and 6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-d]pyrimidines and their inhibitory activity on platelet aggregation

The synthesis of 4-substituted 5,6-dihydrobenzo[h]quinazolines and 6,7-dihydro-5H-benzo[6,7]cyclohepta-[1,2-d]pyrimidines with substituents which are an electron-attracting group such as a nitrite, an amide, a thione, or a carboxyl group is described. Their inhibitory activity against collagen-induced platelet aggregation was also investigated.     

New synthesis of chalcogenolactones. 1H,3H-benzo[c]selenophen-1-one, 1H,3H-benzo[c]tellurophen-1-one and the related 3,4-dihydro-1H-2-benzoselenin-1-one and 3,4-dihydro-1H-2-benzotellurin-1-one

The synthesis of three new basic heterocyclic systems namely, 1H,3H-benzo[c]tellurophen-1-one (2-tellurophthalide), 3,4-dihydro-1H-2-benzoselenin-1-one (3,4-dihydro-2-isoselenocoumarin) and 3,4-dihydro-1H-2-benzotellurin-1-one (3,4-dihydro-2-isotellurocoumarin), is reported through the cyclisation of o-(bromoalkyl)benzoyl chlorides.     

Déplacements Chimiques induits en RMN par un Réactif Lanthanidique: II—Analyse Conformationnelle de Sulfinamates Cycliques: Oxo-2 Oxathiazannes-1,2,3 et Oxo-2 Benzo-5,6 Dihydro-3,4 Oxathiazines-1,2,3

Re-examination of recent results in the literature about 2-r-substituted 5-c-tert-butyl-1,3,2-dioxaphosphorinanes and 3,3-dimethyl-1-oxothiethan made us select, under the indicated conditions, the static model because it is easier to use than the dynamic one. Its application to 17 cyclic sulphinamates belonging to two series—the 2-oxo-1,2,3-oxathiazans (I) and the 5,6-benzo-3,4-dihydro-2-oxo-1,2,3-oxathiazins (II)—confirms, in the presence of Eu(fod)₃, the structures established without the shift reagent, from chemical shifts and coupling constants only, and shows their conformational diversity. For the series (I) the following conformations are found: (i) standard chairs with an axial S?O group (CA) when the molecule is not substituted in the 4 and 6 positions or when the substituents are equatorial (with the exception of 3-tert-butyl-4-t-methyl-2-r-oxo-1,2,3-oxathiazan); the substituents R?Me, iPr or tBu on the nitrogen atom are preferentially axial; (ii) strained chairs with axial Me-4 and S?0 groups (CA); in this conformation R?Ph may be partially conjugated and R?Me or tBu may prefer the more favourable axial orientation; (iii) twist conformations with a 1,4-axis and an axial S?O group (COA) for the two 4-c,6-c- and 4-t,6-c-di-tert-butyl-2-r-oxo-3-phenyl-1,2,3-oxathiazans; (iv) the twist conformation with a 3,6-axis and an axial S?O group (CNA) for trans-3-tert-butyl-4-methyl-2-oxo-1,2,3-oxathiazan because of the 4-methyl—3-tert-butyl 1,2-interaction. For the series (II) half-chair forms with an axial S?O group are proposed.     

Synthesis of new 1,2,3-triazole linked benzimidazole molecules as anti-proliferative agents

One pot click chemistry is used to link triazole and benzimidazole pharmacophore to get N-((1-((1H-benzo[d]imidazol-2-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)aniline and its derivatives. Flexible linkages in the form of –CH₂–R or –O–R/–N–R were designed during synthesis. All the newly synthesized compounds were characterized by FT-IR and NMR spectroscopy as well as high-resolution mass spectrometry. Selected compounds were screened for in vitro anti-proliferative activity using National Cancer Institute (NCI)-60 human tumor cell line screening program. The most potent structure N-((1-((1H-benzo[d]imidazol-2-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-4-chloroaniline 7e showed 40% growth inhibition in renal cancer cell line (UO-31) at 10?µM concentration.