Synthesis of 2(3)-ethoxycarbonyl-5,6,7,8-tetrafluorochromones

The hitherto unknown ethyl pentafluorobenzoylpiruvate was prepared by condensing pentafluoroacetophenone with diethyl oxalate. Intramolecular cyclization of this ester or of its copper(II) chelate, as well as of ethyl 2-(ethoxymethylene)pentafluorobenzoylacetate affords 2- and 3-ethoxycarbonyl-5,6,7,8-tetrafluorochromones. Hydrolysis of the latter followed by decarboxylation gives 5,6,7,8-tetrafluorochromone.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 362–364, February, 1993.     

Synthesis ofN-substituted 2-(5,6,7,8-tetrafluoro-4-oxo-1,4-dihydroquinolin-3-yl)glyoxylic acids

Methods for the synthesis of the earlier unknownN-substituted 2-(5,6,7,8-tetrafluoro-4-oxo-1,4-dihydroquinolin-3-yl)glycoxylic acids their esters from copper chelate of ethyl pentafluorobenzoylpyruvate were developed. The structure of intermediate ethyl 4-(R-amino)-2-oxo-3-pentafluorobenzoylbut-3-enoates is discussed. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1234–1239, July, 2000.     

Synthesis of some 5,6,7,8-tetrahydro-4-cinnolone derivatives and 1-methyl-3-arylacetyl-4,5,6,7-tetrahydroindazoles

2-Arylidene-3-oxo-2,3,4,5,6,7-hexahydrobenzo[b]furans 2 react with hydrazine hydrate to afford 5,6,7,8-tetrahydro-4-cinnolones. By methylation, these compounds gave the corresponding N-1 and N-2 methyl derivatives. The mesoionic compounds are obtained, accompanied by 3-arylacetyl-4,5,6,7-tetrahydroindazoles upon reaction of 2 with methylhydrazine.     

Synthesis of the functionally 4-substituted 1-methyl-3-thioxo-2,3,5,6,7,8-hexahydroisoquinolines by S<Subscript>N</Subscript>Vin reaction of 2-acetyl-1-(<Emphasis Type="Italic">N</Emphasis>-morpholinyl)cyclohexene with malonothio(dithio)amides

4-Carbamoyl(thiocarbamoyl)-3-thioxo-2,3,5,6,7,8-hexahydroisoquinolines were synthesized by the S_NVin reaction of 2-acetyl-1-(N-morpholinyl)acetylcyclohexene with malonothio(dithio)amides. The cyclocondensation direction was confirmed with the X-ray diffraction analysis of 1-methyl-3-methylthio-5,6,7,8-tetrahydroisoquinoline-4-carboxamide.     

1-烷（苯）氧基-3-（3，4-亚甲基二氧）苯基-2-丙醇的合成与生物活性研究

黄樟素氧化物与烷氧基钠和苯氧基钠反应，区域选择性地开环加成，生成1-烷 （苯）氧基-3-（3，4-亚甲基二氧）苯基-2-丙醇。该系列化合物具有诱导细胞凋 亡与分化的生物活性。     

Synthesis of 2-acyl-3-methylthiofurans from 3-methylthio-2-pentene-1,5-dione enolates

2-Acyl-3-methylthiofurans 3 are obtained in fair yields from 3-methylthio-2-pentene-1,5-dione enolates 1 by reaction with iodine. In a similar reaction 1-phenyl-3-methylthio-4-nitro-2-buten-1-one gave 3-methylthio-2-nitro-5-phenylfuran 11. In the crystalline state the 2-benzoyl-3-methylthio-5-phenylfuran 3b showed a non-bonded sulfur-oxygen interaction as inferred from an X-ray diffraction determination, with a S····O distance of 2.871(5)Å.     

Tetrahydrochromenylium and -Thiochromenylium Salts from Triketones of the 2-(3-Oxopropyl)cyclohexane-1,3-dione Series

We have worked out the optimal conditions for synthesis of 2,4-diaryl-5-oxo-5,6,7,8-tetrahydrochromenylium and -thiochromenylium salts based on triketones of the 2-(1,3-diaryl-3-oxopropyl)cyclohexane-1,3-dione series. For the first time, along with 5-oxo-substituted salts, we have obtained 5-thioxo-5,6,7,8-tetrahydrothiochromenylium salts. A necessary condition for the formation of the latter on treatment with acids and S-nucleophiles is the presence of electron-donor groups on the aryl substituents of the indicated triketones.     

An alkaloid-like 3-azabicyclo[3.3.1]non-3-ene library obtained from the bridged Ritter reaction

A small, diverse library of novel alkaloid-like compounds was synthesised using the bridged Ritter reaction with (?)-β-pinene and subsequent scaffold derivatisation. Structural diversity was achieved by varying the nitrile used in the reaction and thus provided an understanding of the influence nitriles have on the reaction outcome; it was determined that more nucleophilic nitriles, gave higher yields. Steric factors also determined the selectivity of scaffold types produced, with larger groups producing predominantly alkene products. X-ray crystallography and attempts to derivatise the imines obtained from the bridged Ritter reaction, highlighted the way the imino nitrogen reacted either not at all or in a stereospecific mannor, due to crowding by adjacent substituents. As the compounds contain either the 3-azabicyclo[3.3.1]nonane or 3-azabicyclo[3.3.1]non-3-ene core architecture, they will also be explored for their biological properties, due to the prevalence of bioactive alkaloids containing these core structures.     

Reduction of 3-(2-hydroxyethyl)-1,5-dinitro-3-azabicyclo[3.3.1]non-6-ene

Reduction of the nitro groups in 3-(2-hydroxyethyl)-1,5-dinitro-3-azabicyclo[3.3.1]non-6-ene was studied. The structures of the reaction products were confirmed using ¹H and ¹³C NMR spectroscopy.     

Pyrimido[4,5-f]quinazolines

The corresponding 6-dimethylaminomethylen-5-oxo-5,6,7,8-tetrahydroquinazolines were obtained from reactions of 2-substituted and 2,7-disubstituted 5-oxo-5,6,7,8-tetrahydroquinazolines with the dimethylacetal of DMF. Sixteen 2,8-disubstituted 5,6-dihydropyrimido[4,5-f]quinazolines were obtained from the reaction of 2-phenyl- and 6-(dimethylamino)methylen-5-oxo-2-(4-pyridyl)-5,6,7,8-tetrahydroquinazolines with guanidine and eight amidines. The corresponding 6-hydroxymethylene derivative was obtained by hydrolysis of 6-(dimethylamino)methylen-5-oxo-1-phenyl-5,6,7,8-tetrahydroquinazoline.     

Synthesis and structure elucidation of 3-methoxy-1-methyl-1H-1,2,4,-triazol-5-amine and 5-methoxy-1-methyl-1H-1,2,4,-triazol-3-amine

Previously it was shown that condensation of dimethyl N-cyanodithioimidocarbonate ( 1a ) with methylhydrazine gave predominantly 1-methyl-5-methylthio-1H-,2,4-triazol-3-amine ( 2 ), which was initially identified erroneously as the regioisomer l-methyl-3-methylthio-1H-1,2,4-triazol-5-amine ( 3 ). We have found that reaction of dimethyl N-cyanoimidocarbonate ( 1b ) with methyl hydrazine affords a high yield of 3-methoxy-1-methyl-1H-1,2,4-triazol-5-amine ( 4 ) rather than the regioisomer 5-methoxy-1-methyl-1H-1,2,4-triazol-3-amine ( 5 ). The structure assignment of 4 was confirmed by X-ray crystallographic analysis of the benzenesulfonyl isocyanate adduct 7 . Triazole 5 was obtained after reacting dimethyl N-cyanothioimidocarbonate ( 1c ) with methylhydrazine.     

Synthesis of some new pyrimidine selanyl derivatives

The targeted synthesis of 2-(methylsulfanyl)-6-(furan-2-yl)-4(3H)-selenoxo -pyrimidine-5-carbonitrile failed due to the formation 1-methyl-2-methylsulfanyl-6-oxo -4-(furan-2-yl)-1,6-dihydropyrimidine-5-carbonitrile. A new series of 5,6,7,8-tetrahydro-1-benzo thieno[2,3-d]pyrimidine-4-yl substituted selanyl derivatives were prepared by the reaction of sodium diselenide with 4-chloro-5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine followed by the reaction with chloroacetic acid derivatives such as ethyl chloroacetate, chloroacetamide or chloroacetonitrile. Hydrazinolysis of ethyl (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine- 4-ylselanyl)acetate with hydrazine hydrate gave the corresponding hydrazino derivative. The latter reacted with ethyl acetoacetate, acetylacetone, diethyl malonate, ethoxymethylenemalononitrile or ethyl 2-cyano-3-ethoxyacetate to afford 5-methyl-2-[2-(5,6,7,8-tetrahydro-1-benzothieno [2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazol-3-one, 1-(3,5-dimethylpyrazol-1-yl)-2- (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)ethanone, 1-[2-(5,6,7,8-tetrahydro -1-benzothieno[2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazolidine-3,5-dione and 5-Amino-1-[2-(5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)acetyl]-1H-pyrazol -4-yl substituted carbonitrile or ethyl carboxylate, respectively. The structure of the novel compounds was confirmed by spectroscopic tools (IR, ¹H NMR ¹³C NMR and mass spectra) and elemental analysis.     

Synthesis of New Fused 1,5-Benzodiazepines,Part 3

1,3-Dihydro-4-phenyl-1,5-benzodiazepin-2-one 1 _a was treated with some ylidenecyanothioacetamides to give the corresponding pyrido(2,3-b)benzodiazepines 3– 6. Treatment of compound 1 _a with a mixture of thiophen-2-aldehyde and thiourea or guanidine gave the corresponding 1,3-thiazino- and pyrimido(4,5-b)benzodiazepines 7 and 8. 3-Arylidene derivatives 9 _a–e and 10 were synthesized. Compound 10 was subject to react with 2-(1-methylthio-1′-anilinomethylidene)malononitrile to give oxazino-benzodiazepine 11. Thieno(3,2-b)benzodiazepines 12 _a,b and 13 were synthesized via the reaction of compound 1 _b with sulfur and some active nitriles. [1,3-Dihydro-4-phenyl(1,5)-benzodiazepin-2-ylidene]malononitrile 15was used as synthon to obtain novel pyrido-, pyrano-, benzo-, and thienobenzodiazepines 16–20, respectively. The reaction of compound 1 _b with CS ₂ or PhNCS along with 1,1,3-tricyano-2-aminoprop-1-ene, 2-(1-methylthio-1′-anilinomethylidene)malononitrile, or 1,3-dibromopropane gave the corresponding polyfused benzodiazepines 21– 23, respectively.     

Synthesis of Novel New 2-(2-(4-((3,4-Dihydro-4-oxo-3-aryl quinazolin-2-yl)methyl)piperazin-1-yl)acetoyloxy)-2-phenyl Acetic Acid Esters

Stereoselective diazotization of (S)-2-amino-2-phenyl acetic acid (L-phenyl glycine) (4) with NaNO₂ in 6% H₂SO₄ in a mixture of acetone and water gave optically pure (S)-2-hydroxy-2-phenyl acetic acid (L-mandelic acid) (5). Esterification, gave (S)-2-hydroxy-2-phenyl acetic acid esters (6). The latter was treated with chloroacetyl chloride in the presence of triethylamine (TEA) in dichloromethane (DCM) to yield (S)-2-chloroacetyloxy phenyl acetic acid ester (2). In another sequence, the reaction of 2-(chloromethyl)-3-arylquinazolin-4(3H)-one (9) treated with N-Boc piperazine, followed by deprotection of the Boc group, to obtain 3-aryl-2-((piperazin-1-yl)methyl) quinazolin-4(3H)-one (3). Reaction of 2 with 3 in the presence of K₂CO₃ and KI gave the title compound, 2-(2-(4-((3,4-dihydro-4-oxo-3-arylquinazolin-2-yl)methyl)piperazin-1-yl) acetoyloxy)-2-phenyl acetic acid esters (1). The structures of all the new compounds obtained in the present work are supported by spectral and analytical data.     

6-烷氨(氧)基-3-甲硫基-1H-吡唑并[3,4-d]嘧啶-4(5H)-酮衍生物的合成与生物活性

用六氯乙烷、三苯基膦和5-氨基吡唑衍生物一锅法合成关键中间体膦亚胺。 再利用串联aza-Wittig反应,加入对氯苯基异氰酸酯,进一步和烷基胺或取代酚反应合成了11个未见文献报道的6-烷氨（氧）基-3-甲硫基1H-吡唑并[3,4-d]嘧啶-4(5H)-酮衍生物。 通过1H NMR、EI-MS、IR和元素分析等方法对所合成的化合物进行了结构表征,并测试了它们的杀菌和除草活性。 测试结果表明,部分化合物对稗草(barnyard grass)和油菜(Rape)均表现出了较好的抑制活性。     

Reaction of 2-dimethylaminomethylene-1,3-diones with dinucleophiles. V. Synthesis of 5-acyl-1,2-dihydro-2-oxo-3-pyridinecarbonitriles and 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarboxamides

The reaction of open-chain sym-2-dimethylaminomethylene-1,3-diones Ia-d with sodium cyanoacetamide gave, generally in good yields, 6-substituted 5-acyl-1,2-dihydro-2-oxo-3-pyridinecarbonitriles IIa-d, whereas cyclohexane sym-2-dimethylaminomethylene-1,3-diones Ie-h afforded in general a mixture of 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarbonitriles and 5,6,7,8-tetrahydro-2,5-dioxo-2H-1-benzopyran-3-carboxamides, the latter being isolated in two cases. The reaction of Ie-h with cyanoacetamide in refluxing anhydrous ethanol gave 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarboxamides IIIe-h in excellent yields, whereas Ia-d did not react with the exception of Ia which afforded in good yield 3-pyridinecarboxamide IlIa. Other 3-pyridine-carboxamides were obtained by partial hydrolysis of nitriles IIb,d. 3-Pyridine and 3-quinoline carboxamides were hydrolyzed in satisfactory yields with hydrochloric acid to the corresponding carboxylic acids, which were decarboxylated in good yields to 5-acyl-2(1H)-pyridinones and 7,8-dihydro-2,5(1H,6H)-quinolinediones, respectively, by reflux in quinoline containing a catalytic amount of copper powder.     

Efficient Synthesis of 6-(1H-1,2,4-Triazol-1-yl)-thieno[2,3-d]pyrimidin-4(3H)-ones via an Iminophosphorane

Ethyl 2-amino-4-methyl-5-(1H-1,2,4-triazol-1-yl)thiophene-3-carboxylate 2, obtained from Gewald reaction of 1-(1H-1,2,4-triazol-1-yl)acetone 1 with ethyl cyanoacetate and sulfur, was transferred into iminophosphorane 3. Further reaction of 3 with aromatic isocyanates gave carbodiimides 4, which were treated subsequently with a secondary amine to give 6-(1H-1,2,4-triazol-1-yl)-thieno[2,3-d]pyrimidin-4(3H)-ones 6 in good yields in the presence of a catalytic amount of sodium ethoxide.     

Reactions of 3-substituted 1-aryl-5,6,7,8-tetrafluoroquinolones(cinnolones) with morpholine

1-Aryl-3-ethoxalyl(heteryl)-5,6,7,8-tetrafluoroquinoxalinones(cinnolinones) react with morpholine to give 7-morpholino- and 5,7-dimorpholino derivatives, depending on the reaction conditions.     

Synthesis and herbicidal activity of (Z)-ethoxyethyl 2-cyano-3-(2-methylthio-5-pyridylmethylamino)acrylates

2-Methylthio-5-pyridinemethylene amine was prepared from 2-chloro-5-methylpyridine. Ethoxyethyl 2-cyano-3,3-dimethylthioacrylate was prepared from ethoxyethyl cyanoacetate, carbon disulfide, and dimethyl sulfate in 86.2% yield. Its reaction with 2-methylthio-5-pyridinemethylene amine yielded (Z)-ethoxyethyl 2-cyano-3-methylthio-3-(2-methylthio-5-pyridylmethylamino)acrylate. Ethoxyethyl (Z+E)-2-cyano-3-ethoxyacrylate was synthesized from ethoxyethyl 2-cyanoacetate and triethyl or- thoacetate in 90.7% yield, and its reaction with 2- methylthio-5-pyridinemethylene amine yielded (Z)-ethoxyethyl 2-cyano-3-methyl-3-(2-methylthio-5-pyri-dylmethylamino)acrylate. The structures of all of the products were confirmed by ¹H NMR, elemental analysis, IR, and mass spectroscopy. The herbicidal activities of the products were evaluated, and the results of bioassay showed that (Z)-ethoxyethyl 2-cyano-3-methyl-3-(2-methylthio-5-pyridylmethylamino)acrylate exhibits good herbicidal activity on rape (Brassica napus) at a dose of 1.5 kg/ha. © 2003 Wiley Periodicals, Inc. 15:67–70, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.hc10214     

2-甲硫基-7(5)-取代-3-吡唑并[1,5-a]嘧啶甲酸乙酯的区域选择性合成与2D NMR 研究

利用3-甲硫基-4-乙氧羰基-5-氨基-1H-吡唑分别与甲基/芳基烯胺酮反应, 合成了8种新的化合物2-甲硫基-7-取代-3-吡唑并[1,5-a]嘧啶甲酸乙酯(3a～3g)和2-甲硫基-5-甲基-3-吡唑并[1,5-a]嘧啶甲酸乙酯(4a). 化合物的结构均经元素分析, IR, ¹H NMR, MS所证实, 异构体3a和4a的结构进一步由¹³C NMR, HMQC和HMBC确认. 同时, 探讨了区域选择性合成吡唑并[1,5-a]嘧啶类化合物可能的反应机理, 并对部分化合物杀菌活性进行了测试.