Synthesis of furo[2,3-c]pyran and some properties of 2-amino derivatives of furo- and pyrrolo[2,3-c]pyrans

Thesynthesisof2-amino-5,5-dimethyl-3-cyano-4,5-dihydro-7H-furo[2,3-c]pyrananditspyrroleanalog was accomplished on the basis of 2,2-dimethyltetrahydro-4-pyranone. Their reaction with maleic anhydride, which leads to the formation of 3-amino-4-cyano-6,6-dimethyl-5,6-dihydro-8H-pyrano[c]-phthalic anhydride, was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 316–318, March, 1991.     

Synthesis and some transformations of <Emphasis Type="Italic">N</Emphasis>,2,2-trimethyltetrahydro-2<Emphasis Type="Italic">H</Emphasis>-pyran-4-amine

Reaction of 2,2-dimethyltetrahydro-2H-pyran-4-one with aqueous methanamine, followed by reduction of the Schiff base thus obtained with sodium tetrahydridoborate gave N,2,2-trimethyltetrahydro-2H-pyran-4-amine which was subjected to cyanoethylation with acrylonitrile. The resulting 3-(2,2-dimethyltetrahydro-2H-pyran-4-ylmethylamino)propanenitrile was reduced with lithium tetrahydridoaluminate to N-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-N-methylpropane-1,3-diamine, and some chemical transformations of the latter were studied.     

Preparation of β-(2,2-dimethyltetrahydro-4-pyranyl)-β-oxopropionic acid anilide

A method for the synthesis of -(2,2-dimethyltetrahydro-4-pyranyl)--oxopropionic acid anilide by the successive conversion of methyl 2,2-dimethyltetrahydro-4-pyranyl ketone to an enamine and reaction of the latter with phenyl isocyanate with subsequent hydrolysis in an acidic medium is proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1189–1190, September, 1981.     

Some Transformations of 3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl-2-thioxo-2,3-dihydro-1H-spiro(benzo[h]quinazoline-5,1'-cycloheptan)-4(6H)-one

Russian Journal of Organic Chemistry - Starting from 3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-2-thioxo-2,3-dihydro-1H-spiro(benzo[h]quinazoline-5,1'-cycloheptan)-4(6H)-one, a series of...     

Tetrahydropyran-2,4-diones in the Synthesis of Fused N,O-Heterocycles

Condensation of 6-methyl(or phenyl)-tetrahydropyran-2,4-diones with 2-aminonaphthalene or 6-aminoquinoline and aromatic aldehydes in an aliphatic alcohol gave 5-aryl-2,2-dimethyl(or 2-phenyl)-1,2,5,6-tetrahydro-4H-benzo[f]pyrano[3,4-c]quinolin-4-ones and 5-aryl-2-methyl-1,2,5,6-tetrahydro-4H-pyrano[4,3-a][4,7]phenanthrolin-4-ones which are new N,O-heterocyclic systems containing fused aza- and diazaphenanthrene moieties and a 2-pyranone ring.     

Reaction of α,α-, α,α′-dihalothiones with 8-mercaptoquinolinium halides as a route to tetrahydro-1,4-thiazinoquinolinium halides

The reaction of 8-mercaptoquinolinium bromide with 1,3-dibromopropane-2-thione or 3,3-dibromobutane-2-thione in methanol gave the 2-bromomethyl-2-mercaptotetrahydro-1,4-thiazino[2,3,3,4-i,j]quinolinium and 3-bromo-2-mercapto-2,3-dimethyltetrahydro-1,4-thiazino[2,3,3,4-i,j]quinolinium bromides which readily exchanged the Br⁻ anion for ClO ₄ ⁻ upon treatment with sodium perchlorate in methanol. Oxidation of the 3-bromo-2-mercapto-2,3-dimethyltetrahydro-1,4-thiazino[2,3,3,4-i,j]-quinolinium bromide by selenium dioxide gave 2,2-dithiobis(3-bromo-2,3-dimethyltetrahydro-1,4-thiazino[2,3,3,4-i,j]quinolinium) bromide. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1720–1723, November, 2006.     

Ring-opening polymerization of cyclic urethanes and ring-closing depolymerization of the respective polyurethanes

The cationic ring-opening polymerization of trimethylene urethane (tetrahydro-2 H-1,3-oxazin-2-one) in the melt with methyl trifluoromethanesulfonate as initiator results in poly(trimethylene urethane) in yields of ≈70%. Under the same reaction conditions 2,2-dimethyltrimethylene urethane (5,5-dimethyltetrahydro-2H-1,3-oxazin-2-one) cannot be polymerized. Poly(2,2-dimethyltrimethylene urethane), however, was obtained via polycondensation polymerization. Both polymers exhibit a uniform microstructure as deduced from NMR spectroscopic analysis. Ring-closing depolymerization in the melt with dibutyltin dimethoxide or titanium tetraisopropoxide at 140°C results the respective monomers in yields of ≈90%.     

Synthesis of 2,2,3,3-tetracyanocyclopropyl ketones and their reactions with oxygen-centered nucleophiles

A procedure for the synthesis of 2,2,3,3-tetracyanocyclopropyl ketones has been developed on the basis of three-component Wideqvist reaction of dihydroxymethyl ketones, 2-bromomalononitrile, and malononitrile. The presence of five electron-withdrawing groups in the resulting cyclopropyl ketones determines high acidity of proton in the cyclopropane ring. Facile deprotonation by the action of bases promotes opening of the three-membered ring with formation of either 1,1,3,3-tetracyanopropenides or (in the presence of alcohols or oximes), [2-alkoxy(aminooxy)-5-amino-4-cyanofuran-3(2H)-ylidene]malononitriles. The reaction with acetone oxime was not accompanied by cleavage of the three-membered ring, and nucleophilic attack was directed at the cyano groups in the trans position with respect to the carbonyl group to give the corresponding (1R*,5S*,6R*)-4-amino-2,2-bis(prop-2-ylideneaminooxy)-3-azabicyclo[3.1.0]hex-3-ene-1,5-dicarbonitriles.     

New example of the enamine rearrangement of pyrimidines

Erevan Institute on the National Economy, Erevan 375025. Translated From Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1577–1578, November, 1995. Original article submitted november 29, 1995.     

A proposed structure for the copper(ii) salts of α-acyloin oximes

The behavior of the copper (II) salts of the a-isomers of some acyloin oximes towards a series of selected amines was examined in order to study the unusual solubility relationships which these copper salts exhibit towards ammonium hydroxide. The insolubility in ammonium hydroxide of these copper salts of acyloin oximes has been attributed to their being inner complex salts. Evidence is presented which is contra y to this view. Based on the solubilities of the copper (II) salts investigated, a polymeric structure for copper (II) acyloin oximes is proposed. The study included the following α-isomers of acyloin oximes: benzoin oxime, 2,2'-furoin oxime, phenylbenzoin oxime, methylbenzoin oxime, 2,2'thenoin oxime, a-hydroxyisobutyrophenone oxime, and α-hydroxyacetophenone oxime. The last four compounds had not been examined previously as to their ability to form copper (II) salts.     

Condensed Pyridopyrimidines. 2. Synthesis of New Derivatives of Pyranopyrido[2,3-d]pyrimidines

New condensed derivatives of pyrido[2,3-d]pyrimidines were synthesized using the morpholine enamine of tetrahydro-4-pyranone.     

Design,Synthesis, and Bioactivity Evaluation of Novel 3‐(Substituted Phenoxy)‐6‐Methyl‐4‐(3‐Trifluoromethylphenyl) Pyridazine Derivatives

Using 3‐(4‐cyano phenoxy)‐6‐methyl‐4‐(3‐trifluoromethylphenyl) pyridazine (compound A ) as a leading compound, a total of 24 novel 3‐(substituted phenoxy)‐6‐methyl‐4‐(3‐trifluoromethylphenyl) pyridazine derivatives containing two electron‐withdrawing groups on the benzene ring (acylamine and oxime ether) were synthesized. Their herbicidal, insecticidal activities were bioassayed, and the herbicidal activity of compound CD-2 against Brassica campestris was 97.6% at 300 g/ha, which was better than the commercial herbicide diflufenican at the this concentration and is equal to the activity of the leading compound A . Compound CD-4 , CD-5 , CJ-3 , and CJ-5 displayed excellent insecticidal activity against Aphis laburni Kaltenbach (>95%). The results show that the oxime ether substitutions exhibit better bleaching and herbicidal activity than the acylamine ones. The bleaching and herbicidal activity of para‐position substitutions is better than the meta‐position ones. It seems that the para‐position on the benzene ring of oxime ether pyridazine derivatives is one of the key active sites that affect their herbicidal activities.     

Reaction of acetone oxime with dialkylmalonyl chlorides. Synthesis of 2-(2-propenyl)isoxazolidine-3,5-diones and 2,2-bis-(2-(4,4-dialkylisoxazolidine-3,5-dione))propanes

Reaction of acetone oxime with dialkylmalonyl chlorides in the presence of triethylamine gave as products 2-(2-propenyl)-4,4-dialkylisoxazolidine-3,5-diones 4 and 2,2-bis-(2-(4,4-dialkylisoxazolidine-3,5-dione))propanes 5 . The 4,4-dialkylisoxazolidine-3,5-diones 6 and dimethylketoximyl 4,4-dialkylmalonates 7 were formed as minor products. Compounds 4 are stable in refluxing ethanol and in aqueous solution. Compounds 5 are stable when heated in refluxing toluene in the presence of either pyridine or monochloroacetic acid.     

替格瑞洛的合成工艺改进

以2-丙硫基-4,6-二氢-5-氨基嘧啶和2-{［(3aR,4S,6R,6aS)-6-氨基-2,2-二甲基四氢-3aH-环戊基［d］［1,3］二氧-4-基］氧}-1-乙醇L-酒石酸盐为原料,经C-N偶联,亲核取代和环合反应制得2-{［(3aR,4S,6R,6aS)-6-(7-氯-5-丙硫基-3H-［1,2,3］三唑［4,5-d］嘧啶-3-基)-2,2-二甲基四氢-3aH-环戊基［d］［1,3］二氧-4-基］氧}-1-乙醇(4); 4与(1R,2S)-2-(3,4-二氟苯基)环丙胺D-扁桃酸盐经亲核取代反应后酸解脱除丙酮叉保护基合成替格瑞洛,总收率58.7%,纯度99.2%,其结构经¹H NMR, MS(ESI)和XRD确证。     

Synthesis of 1-azapyrene

The environmental contaminants 1-azapyrene 15 , 2-azapyrene 13 and several other azapyrene derivatives were synthesized from a common intermediate, 2,2a,3,4-tetrahydrocyclopenta[cd]phenalen-1-one oxime 6 . The synthesis of 1-azapyrene 15 completes the series of azapyrenes.     

合成(±)顺式-3-(二氯乙烯基)-2,2-二甲基环丙烷羧酸的新方法

本文报道两种从5-氯-3,3-二甲基戊酸乙酯(4)合成±)-顺式-3-(二氯乙烯基)-2,2-二甲基环丙烷羟酸(±)的方法.中间体4,4-二甲基-3,4-二氢-2-吡喃酮(3)是从化合物(4)经水解皂化,酸化和氧得到3,3-二甲基戊醛酸甲酯(6),再皂化得到3,3-二甲基戊醛酸(8),然后环化得到;或者由化合物4经苯基硫醚化,氧化得到8,然后环化后得到.     

Solubilities of iron(III) complexes of 3-hydroxy-2-ethyl-4-pyranone and of 3-hydroxy-1,2-dimethyl-4-pyridinone in aqueous salt solutions

Solubilities are reported for the tris-ligand–iron(III) complexes of 3-hydroxy-2-ethyl-4-pyranone and of 3-hydroxy-1,2-dimethyl-4-pyridinone in aqueous solutions of alkali halides and of ammonium and tetraalkylammonium bromides. The Setchenow coefficients estimated from salt effects on solubilities for these complexes are compared with those for other inorganic complexes.     

双核茂铁四氮唑的合成及对高氯酸铵热分解的催化作用

首先以二茂铁为原料合成丙基桥联的双聚二茂铁(DFP), 经甲酰化得到丙基桥联的双聚二茂铁甲醛(DFP-CHO, 1), 再与NH₂OH·5HCl进行缩合反应得到双核二茂铁肟(2), 然后脱水得到丙基桥联双聚二茂铁甲腈(3), 最后在(n-C₄H₉)₃SnCl 的催化作用下与NaN₃进行[2+3]环加成反应, 生成目标产物丙基桥联双聚二茂铁四唑(4); 通过¹H NMR, FTIR和ESI-MS对目标产物的结构进行了表征. 利用差示扫描量热分析(DSC)和热重(TG)分析研究了这2个双聚二茂铁氮杂衍生物的燃速催化性能, 结果表明, 通过添加质量分数为5%的丙基桥联双聚二茂铁氮杂化合物3和4均使高氯酸铵(AP)的热分解温度降至100℃左右.     

Reactions of 1,3-dihydrobenzo[<Emphasis Type="Italic">c</Emphasis>]thiophene 2,2-dioxides with electrophilic agents

Nitration, sulfonation, and iodination of 1,3-dihydrobenzo[c]thiophene 2,2-dioxide and its derivatives with electron-releasing and electron-withdrawing substituents were studied. Electrophilic substitution in 1,3-dihydrobenzo[c]thiophene 2,2-dioxide occurs at position 5. The presence of electron-withdrawing substituents in this position hinders further substitution, while electron-releasing substituents in positions 5 and 6 direct an electrophile to position 4.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 428–431, February, 2005.     

Quantum chemical and experimental studies on the structure and vibrational spectra of substituted 2-pyranones

A systematic study on the structural characteristics of the 2-pyranone ring containing molecules with bromine, nitrile, and amide substituents at the C-3 position in the ring is conducted in the electronic ground (S ₀) state by DFT calculations using the B3LYP/6-311++G** method. The geometrical structure of the bromine substituted compound, which shows potent hepatoprotective activity, is studied both in the ground (S ₀) and first excited singlet (S ₁) states using RHF/6-311++G** and CIS/6-311++G** methods respectively. The molecules are found to exist in two isomeric forms gauche and trans that have the enthalpy difference of less than 3.32 kcal/mol; the latter is the preferred orientation in the gaseous phase. The S ₁ state is a ¹(π,π*) state that arises π-electron transfer from the region of a double bond in the pyranone ring to the region of the internuclear bond connecting the 2-pyranone and benzene rings. A complete vibrational analysis is conducted for the 3-bromo-6-(4-chlorophenyl)-4-thiomethyl-2H-pyran-2-one molecule based on the experimental infrared spectra in the 50–4000 cm⁻¹ region and DFT/6- 311++G** computations of vibrational frequencies for the gauche and trans isomeric forms. Spectral assignments based on the potential energy distribution along the internal coordinates confirm the nonplanar structure of the molecule.