Crystal and Molecular Structure of 2,3-Tetramethylen-3,4-dihydroquinazoline

The crystal and molecular structure of the alkaolid 2,3-tetramethylen-3,4-dihydroquinazoline hydrochloride was solved by X-ray structure analysis. It was demonstrated that the crystal contains an aqua system similar to those in the isostructural 2,3-trimethylen-3,4-dihydroquinazoline (deoxypeganine), and 2,3-pentamethylen-3,4-dihydroquinazoline hydrochlorides.     

Chemical modification of the alkaloid 2,3-tetramethylene-3,4-dihydroquinazol-4-one

The 1,2-dihydro derivative of 2,3-tetramethylene-3,4-dihydroquinazol-4-one was produced by reduction and characterized using NMR spectra. 1-Acyl-1,2,3,4-tetrahydroquinazol-4-ones and ureas were synthesized by acylation of 2,3-tetramethylene-1,2,3,4-tetrahydroquinazol-4-one with acid chlorides and arylisocyanates, respectively. The molecular structures of 1-acetyl-and-m-chlorophenylaminocarbonyl-2,3-tetramethylene-1,2,3,4-tetrahydroquinazol-4-ones were established using x-ray structure analyses. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 364–370, July–August, 2007.     

Synthesis of 2,3-tetramethylene-5-arenesulfonamidobenzofurans

The reaction of N-arenesulfonyl-1,4-benzoquinonimines with 1-morpholino(piperidino)-1-cyclohexene gives 2,3-dihydro-2-morpholino(piperidino)-2,3-tetramethylene-5-arene-sulfonamidobenzofurans. Refluxing of the latter in dilute hydrochloric acid gave 2,3-tetramethylene-5-arenesulfonamidobenzofurans, the structure of which was proved by hydrolysis to 2,3-tetramethylene-5-aminobenzofuran and conversion of it to the previously described 2,3-tetramethylene-5-hydroxybenzofuran.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 872–874, July, 1972.     

2-氰基-3,4-二氢喹唑啉衍生物的合成

邻硝基苯甲醛与取代苯胺(1)或取代苄胺(2)进行还原氨化反应得N-(2-硝基苄基)取代苯胺(3)或N-(2-硝基苄基)取代苄胺(4);将3或4的硝基还原为氨基生成关键中间体N-(2-氨基苄基)取代苯胺(5)或N-(2-氨基苄基)取代苄胺(6);5或6分别与4,5-二氯-1,2,3-二噻唑氯化物进行缩合反应,合成了一系列新的2-氰基-3,4-二氢喹唑啉类衍生物,收率36%~72%,其结构经1H NMR和HR-MS确证。     

Synthesis of 3-amino-4-methyl-6-trifluoromethylthieno[2,3-b]pyridine-2-carboxanilide and its crystal and molecular structure

4-Methoxy-1,1,1-trifluoropent-3-en-2-one reacts with cyanothioacetamide to give 3-cyano-4-methyl-6-trifluoromethylpyridine-2(1H)-thione, which was transformed into 3-amino-4-methyl-6-trifluoromethylthieno[2,3-b]pyridine-2-carboxanilide by the reaction with chloroacetanilide. The crystal and molecular structure of the amide obtained was studied by X-ray analysis. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 4, pp. 701–703, April, 1998.     

Synthesis and crystal structure of ethyl 1-benzyl-2-hydroxy-5-methyl-3-oxo-2-phenacyl-2,3-dihydropyrrole-4-carboxylate

Reaction of 5-phenyl-2,3-dihydro-2,3-furandione with ethyl 3-benzylamino-2-butenoate, resulting in ethyl 1-benzyl-2-hydroxy-5-methyl-3-oxo-2-phenacyl-2,3-dihydropyrrole-4-carboxylate and benzylamide ofN-benzoylpyruvic acid, was studied. The structure of the pyrrole derivative was confirmed by X-ray analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1552–1555, August, 1995.     

Synthesis and structure of 6-chloro-2,3-trimethylene-4-phenylquinoline

An X-ray structural investigation of 6-chloro- 2,3-trimethylene-4- phe nylquinoli ne obtained by the reaction of 2-amino-5-chlorobenzophenone with cyclopentanone was carried out. At 20 °C, a = 23.750,b = 9,242, c = 14.018 A, = 112,68° space group (21c,Z = 8, 2647 reflections,R = 0.047 He five-membered ring has an envelope conformation Conjugation between the quinohne fragment and the phenyl substituent is significantly distorted dm to the rotation of the latter by -62.9°Translated fromIzvestiya Akademii Nauk. Seriva Khimicheskaya, No. 7, pp. 1800–1802, July, 1996.     

Synthesis of some cyclopentenones and crystal structure of 4-hydroxy-3,4-bis(4-methoxyphenyl)-5,5-dimethyl-2-cyclopenten-1-one

Abstract  

Sodium-hydroxide-catalyzed condensation of di-p-methyl- and di-p-methoxybenzil with acetone derivatives was investigated in methanol. Di- and trisubstituted products were obtained as cyclopentenones, while tetraaryl-substituted systems were isolated as cyclopentadienones. The structures of the products were identified by elemental analysis, infrared (IR), nuclear magnetic resonance (¹H NMR), and mass spectroscopy. The solid-state structure of 4-hydroxy-3,4-bis(4-methoxyphenyl)-5,5-dimethyl-2-cyclopenten-1-one was further studied by single-crystal X-ray diffraction analysis. The title compound crystallizes in an orthorhombic space group and intermolecular O–H···O and C–H···O hydrogen bonds stabilize the crystal lattice.     

Synthesis and three-dimensional structure of 4-hydroxy-4-methyl-3-chloro-6-alkyltetrahydropyrans

A method has been developed for the preparation of 4-hydroxy-4-methyl-3-chloro-6-alkyltetrahydropyrans based on the cycloalkylation of 4-hydroxy-2-methyl-3-chloro-1-butene with aldehydes. Dehydrochlorination of these compounds furnished the corresponding oxiranes of the tetrahydropyran series. The chlorine atoms in these newly synthesized chlorotetrahydropyranols have been found to favor equatorial positions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1457–1460, November, 1986.     

Synthesis of cis-3,4-dibromopyrrolidine and its crystal and molecular structure

Synthesis and structural studies of 3,4-dibromopyrrolidine hydrochloride are reported. The conformation of the dibromopyrrolidine ring is a slightly deformed envelope with ΔC_s(3–4) = 4.03°. The Br atoms have cis conformation. Short Cl?H—N hydrogen bonds link the 3,4-dibromopyrrolidine cations and Cl^? anions along the a-axis.     

Ring — chain tautomerism and reactions of 4-aryl-4-hydroxy-2,3-dimethyl-3,4-dihydrophthalazinones

It has been established by IR spectroscopy that the N,N-dimethylhydrazides of 2-aroylbenzoic and benzil-o-carboxylic acids, with the exception of 2-mesitoylbenzoic acid, have the ring structure of 4-aryl- or 4-benzoyl-4-hydroxy-2,3-dimethyl-3,4-dihydrophthalazinones. The action of electrophilic agents on 4-hydroxy-2,3-dimethyl-4-phenyl-3,4-dihydrophthal-azinone under mild conditions leads to N₍₃₎-demethylation with the formation of 2-methyl-4-phenylphthalazinone.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1124–1126, August, 1973.     

Synthesis and structure of 8-hydroxy-6-methoxy-3,7-dimethylisochromane and its analogues

The title compound 1 was obtained by the reaction of alcohol 18 and triethyl orthoformate catalyzed by aluminum chloride followed by catalytic hydrogenation in good yield. Similarly, compounds 1 and 3 were obtained by intramolecular cyclization of MOM ether 19 with titanium(IV) chloride in moderate yields and isochromanes 1, 3, 26 and 27 by intramolecular cyclization of ether 20 with titanium(IV) chloride in high yields. The structures of compounds 1-3 were elucidated by analysis of spectroscopic data and chemical reactions. The mechanisms on the formation of 1 and 3 are discussed.     

Molecular and crystal structures of 6-substituted 4-phenylquinazoline 3-oxides and 2,2,6-trimethyl-4-phenyl-1,2-dihydroquinazoline

Single crystal X-ray diffraction (XRD) has been employed for the determination of crystal and molecular structures of three 6-substituted 4-phenylquinazoline 3-oxides. Characteristic features of the structures have been revealed, intermolecular interactions have been considered.     

IR spectra and crystal structure of hydrochlorides and complex salts of 2,3-polymethylene-3,4-dihydroquinazolines and-4-quinazolones

IR spectra are reconsidered on the basis of the results of x-ray structural analysis of the crystal structures of hydrochlorides and complex salts of 2,3-polymethylene-3,4-dihydroquinazolines and-4-quinazolones. It has been established that two absorption bands (Nl⁺–H) in the complex salts characterize different energies of formation of an H-bond, which is weaker than in the corresponding hydrochlorides. The nature of an absorption band in the 3400–3500 cm^–1 region has been established from the XSA results.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 364–367, May–June, 1999.     

Synthesis and structure of 4-hydroxy-3-pyridylcoumarins

The reaction of substituted 3-cinnamoyl-4-hydroxycoumarins with pyridinium salts of various bromomethyl ketones gives the corresponding 4-hydroxy-3-pyridylcoumarins. The use of microwave radiation decreases the time required and improves the yield of this reaction. The products obtained do not display solvatochromic properties or photochemical activity.     

新试剂6-溴-2-苯并噻唑重氮氨基偶氮苯的合成及其与汞(Ⅱ)的显色反应

报道了6 溴 2 苯并噻唑重氮氨基偶氮苯(BBTDAA)的合成及其与汞(Ⅱ)的显色反应。在TritonX 100存在下,于pH10.8的Na2B4O7 NaOH缓冲体系中,Hg(Ⅱ)与BBTDAA形成1∶4的红色配合物,试剂与配合物的最大吸收波长分别为430nm和515nm,表观摩尔吸光系数为1.88×105L/mol·cm。汞在0～0 32μg/mL范围内符合比尔定律。用拟定的方法测定了湖水和废水中的汞。     

Molecular and crystal structure of 2H-3,4-dihydro-3-hydroxy-3-oxo-1,5,3-benzodioxaphosphepine

Conclusions An x-ray diffraction structural analysis was carried out for 2H-3,4-dihydro-3-hydroxy-3-oxo-1,5,3-benzodioxaphosphepine and the seven-membered heterocycle in this molecule was found to have chair conformation with an axial OH group.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1429–1431, June, 1988.