Pyrano[4,3-d]pyrimidinium salts 3. Reactions of 1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium salts with azomethines

Reactions of 1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium salts with azomethines have been studied. The reactions lead to 1,3-dimethyl-2,4-dioxo-1H,3H-pyrido-[4,3-d]pyrimidinium salts and aromatic aldehydes.     

4-functionally substituted 3-heterylpyrazoles: XVIII. Intramolecular cyclization of N -[3-(2-Chlorophenyl)-4-pyrazolyl]methylamine and its N-alkyl derivatives into 4,5-dihydro-2 H -pyrazolo[4,3- c ]quinolines

N-[3-(2-Chlorophenyl)-4-pyrazolyl]methylamine and its N-alkyl-derivatives at heating in DMF in the presence of K₂CO₃ undergo an intramolecular cyclocondensation yielding 4,5-dihydro-2H-pyrazolo[ 4,3-c]quinolines. Original Russian Text ? M.K. Bratenko, O.I. Panimarchuk, V.A. Chornous, M.V. Vovk, 2007, published in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 8, pp. 1213–1216. For Communication XVII see [1].     

One-step Synthesis of 3,4-Dihydrobenzimidazo[2,1- b ]quinazolin-1(2 H )-ones in an Ionic Liquid

A novel class of 3,4-dihydrobenzimidazo[2,1-b]quinazolin-1(2H)-ones was synthesized in very short reaction times with good yields in the presence of 3-butyl-1-methyl imidazolium bromide as a room temperature ionic liquid at 120°C. The ionic liquid can be recycled for subsequent reactions without any loss of efficiency.     

Spirane—III 3,3′-spirobi[benzo-[2H.4H]-[1.5]-dioxepin]

The conformation of the mentioned new spiran system has been determined by NMR spectroscopy. It contains two heterocyclic rings in the chair form, is chiral and shows a twofold axis of symmetry.     

Regioselective Synthesis ofPyrano[3,2- f ]quinolin-2(7 H )-onesand Furo[3,2- f ]quinolin-2-ones

 A simple and efficient synthesis of the hitherto unreported ring systems pyrano[3,2-f]quinolin-2(7H)-one and furo[3,2-f]quinolin-2-one was accomplished via a thermal [3,3]-sigmatropic rearrangement.     

Synthesis and properties of photoacylotropic (2Z)-2-(N-acyl-N-arylaminomethylidene)benzo[b]thiophen-3(2H)-ones with a chiral migrating group

New photochromic (2Z)-2-(N-acyl-N-arylaminomethylidene)benzo[b]thiophen-3(2H)-ones containing L-amino acid derivatives as migrating groups were synthesized. Light irradiation of their solutions at 436 nm leads to the photoinduced acylotropic rearrangement N → O accompanied by migration of the chiral fragment. The bulky N-acyl group causes steric strain thus destabilizing the amide form of compounds and facilitating the photorearrangement. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2690–2696, December, 2005.     

Five-membered 2,3-dioxoheterocycles: LXXXIV. [4+2]-Cycloaddition of styrene to 4,5-diaroyl-1H-pyrrole-2,3-diones. Crystal and molecular structures of 7a-(2,5-dimethylbenzoyl)-4-(2,5-dimethylphenyl)-1-(4-methoxyphenyl)-6-phenyl-7,7a-dihydropyrano[4,3-b]-pyrrole-2,3(1H,6H)-dione

1-Aryl-4,5-diaroyl-1H-pyrrole-2,3-diones react with styrene to form substituted 7,7a-dihydropyrano[4,3-b] pyrrole-2,3(1H,6H)-diones whose structure was confirmed by XRD analysis. The crystal and molecular structure of 7a-(2,5-dimethylbenzoyl)-4-(2,5-dimethyl-phenyl)-1-(4-methoxyphenyl)-6-phenyl-7,7a-dihydropyrano[4,3-b] pyrrole-2,3(1H,6H)dione was examined.     

Reactions of 4-(2-aminothiazole-4-yl)-3-methyl-5-oxo-1-phenyl-2-pyrazoline. Synthesis of thiazolo[3,2- a ]pyrimidine and imidazo[2,1- b ]thiazole derivatives

4-(2-Aminothiazol-4-yl)-3-methyl-5-oxo-1-phenyl-2-pyrazoline was synthesized via the reaction of 4-bromoacetyl-3-methyl-5-oxo-1-phenyl-2-pyrazoline with thiourea [7] and was transformed to related fused heterocyclic systems. The antifungal and antibacterial studies revealed in some cases excellent biocidal properties.     

Synthesis and structure of 2-aryl-4 H -acenaphth[5,6- bc ]oxepin-4-ones

Oxidation of 2-aryl-7,8-dihydro-4H-acenaphth[5,6-bc]oxepin-4-ones with chloranil led to the formation of 2-aryl-4H-acenaphth[5,6-bc]oxepin-4-ones. Their spectral characteristics were analyzed, and a calculation of the molecular structure of model and real compounds was carried out. Original Russian Text ? R.V. Tyurin, A.A. Milov, A.N. Bezuglov, A.N. Antonov, L.G. Minyaeva, V.V. Mezheritskii, 2007, published in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 10, pp. 1474–1478.     

Synthesis and anticancer activity of some 1,5-diaryl-3-(3,4,5-trihydroxyphenyl)-1H-pyrazolo[4,3-e][1,2,4]triazines

Abstract  

The deregulation of cell cycle components in cancer cells has provided a rationale for the development of small molecule inhibitors of cyclin-dependent kinases as novel anticancer drugs. A series of 1,5-diaryl-3-(3,4,5-trihydroxyphenyl)-1H-pyrazolo[4,3-e][1,2,4]triazines was synthesized and their kinase inhibitory activity and cytotoxicity against several cancer cell lines has been evaluated. Some of the compounds of the series exhibited induction of caspase-dependent cell death and inhibition of cyclin-dependent kinase 2 (CDK2).     

Synthesis of 1,2,4-Triazol-3-ylmethyl-, 1,3,4-Oxa-, and -Thiadiazol-2-ylmethyl-1H-[1,2,3]-triazolo[4,5-d]pyrimidinediones

1-Carbethoxymethyl-4,6-dimethyl-1H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-dione was synthesized and treated with hydrazine hydrate to give the corresponding hydrazide. The latter hydrazide was treated either with phenylisothiocyanate or with carbon disulfide/alc. KOH to afford the corresponding thiosemicarbazide and oxadiazole derivatives. Alkylation of 2-mercapto-1,3,4-oxadiazole with dimethyl sulfate or ethyl chloroacetate gave the corresponding 2-methylthio-, and 2-ethylthioglycolate derivatives. Formation of 1,3,4-thiadiazole, 5-mercapto-1,2,4-triazole, and 1,3,4-oxadiazole were carried out by treating of the latter thiosemicarbazide with conc. H₂SO₄, NaOH/HCl, and HgO. Treating of 5-mercapto-1,2,4-triazole with ethyl chloroacetate afforded the thioglycolate ester. Hydrolysis of the latter with hydrazine hydrate afforded the hydrazide derivatives. Condensation of these hydrazides with monosaccharide aldoses gave the corresponding sugar hydrazones. The novel compounds were tested for antiviral activity against hepatitis B virus and showed moderate activities.     

3-(2-苯并呋喃酰基)薁-1-羧酸甲酯的有效合成

以苯基三甲铵三溴盐(PTAB)为溴化试剂, 对3-乙酰基薁-1-羧酸甲酯进行了溴代反应研究, 将其单溴代产物与水杨醛在温和反应条件下进行缩合, 以极优的收率高选择性得到3-(2-苯并[b]呋喃酰基)薁-1-羧酸甲酯类衍生物, 其结构经¹H NMR, IR及元素分析等得以证实.     

The position of electrophilic substitution of 2-methyl-2H-cyclopenta[d]pyridazine and the crystal structures of two substitution products

2-Methyl-2H-cyclopenta[d]pyridazine reacts with trifluoracetic anhydride to give the 5- and 7-trifluoroacetyl products in about a 1:3 ratio. A series of HMO calculations have been made for similar ten π-electron heterocycles in an attempt to predict the positions in the 5-membered rings which would be most reactive to electrophilic substitution. The predictions based on the relative π-electron stabilities of the possible cationic intermediates are in accord with the available experimental data. If the atoms in the 6-ring are numbered 1-6 with the π-excessive heteroatom at the 1-position, then the most reactive site to electrophilic substitution in the 5-ring will be the atom which is linked to either the 1-, 3- or 5-positions. The structures of the major and minor trifluoroacetyl isomers of 2-methyl-2H-cyclopenta[d]pyridazine have been determined by X-ray crystallographic analyses, and the HMO predictions agree with the finding that C(7) is the most reactive position. 2-Methyl-5-trifluoroacetyl-2H-cyclopenta[d]pyridazine crystallizes in the monoclinic space group P2₁/m, cell constants a = 8·109, b = 6·713, c = 8·768 Å, β = 91·88°, with two molecules per unit cell. All of the atoms have been located and refined by full-matrix least-squares and the final residual is 0·056. The bond lengths appear to be influenced by a contribution of a pyridazinium form to the resonance hybrid. 2-Methyl-5-bromo-7-trifluoroacetyl-2H-cyclopenta[d]pyridazine crystallizes in the orthorhombic space group Pnam, cell constants a = 12·920, b = 12·513, c = 6·752 Å, with four molecules per unit cell. Although the quality of the diffraction data was severely limited by rapid decomposition of the specimen in the X-ray beam, the gross features of the structure were revealed. The residual following isotropic refinement was 0·19.     

2-取代氨基-6-甲基-5-氧代-4-正丁基-4,5-二氢-1,2,4-三氮唑并[1,5-a]嘧啶类衍生物的合成

以2-溴丙酸甲酯、α,α-二氯甲基甲醚和胍唑为原料, 经缩合以及环化反应制得2-氨基-6-甲基-5-氧代-4,5-二氢-1,2,4-三氮唑并[1,5-a]嘧啶. 为了提高其在有机溶剂中的溶解性, 该化合物再同1-溴丁烷发生亲核取代反应得到了2-氨基-6-甲基-5-氧代-4-正丁基-4,5-二氢-1,2,4-三氮唑并[1,5-a]嘧啶, 然后与芳基醛和叔丁基异氰发生Ugi多组分反应, 合成了一系列具有潜在催吐活性的2-取代氨基-6-甲基-5-氧代-4-正丁基-4,5-二氢-1,2,4-三氮唑并[1,5-a]嘧啶类衍生物, 产品结构经质谱、核磁共振谱及元素分析确认.     

7-取代苯氧基-4,5-二氢-1,2,4-三唑并[4,3-a]喹啉和喹啉-1(2H)-酮衍生物的合成及抗惊厥活性

合成了7-取代苯氧基-4,5-二氢-1,2,4-三唑并[4,3-a]喹啉(3a～3g)和7-取代苯氧基-4,5-二氢-1,2,4-三唑并[4,3-a]喹表明啉-1(2H)-酮(4a～4g)类衍生物. 以最大电惊厥法和戊四唑法测定了抗惊厥活性, 以旋转棒法测定了神经毒性. 结果表明, 化合物7-(4-氟苯氧基)-4,5-二氢-1,2,4-三唑并[4,3-a]喹啉-1(2H)-酮(4c)显示最强的抗惊厥作用和低的神经毒性, 其抗电惊厥ED₅₀为6.8 mg/kg, 神经毒性TD₅₀为88.0 mg/kg, 保护指数PI为12.9, 明显优于对照药苯妥英钠.