Crystal structure of a liquid crystal non‐symmetric dimer: cholesteryl 4‐[4‐(4‐n‐butylphenylethynyl)phenoxy]butanoate

The crystal structure of cholesteryl 4‐[4‐(4‐n‐butylphenylethynyl)phenoxy]butanoate [phase sequence: Cr 155°C (46.1?J?g^?1) SmA 186.8°C (1.5?J?g^?1) TGB‐N* 204.7 (6?J?g^?1) I] has been solved from single crystal X‐ray diffraction data. The compound crystallizes in the monoclinic space group P2₁ with unit cell parameters: a?=?13.129(2), b?=?9.3904(10), c?=?17.4121(8)?Å, β?=?92.790(7)°, Z?=?2. The structure has been solved by direct methods and refined to R?=?0.0606 for 3?250 observed reflections. The bond distances and angles are in good agreement with the corresponding values for compounds containing phenyl and cholesterol moieties. The phenyl rings A and B are planar. The dihedral angle between the least‐squares planes of the two phenyl rings is 28°. The cholesterol moiety has the usual structure: the C and E rings have chair conformations, and the D and F rings adopt half‐chair conformations. The molecules in the unit cell are arranged in an antiparallel manner. The crystal structure is stabilized by an intermolecular C–H…O contact of 2.989(10)?Å.     

Crystal structure of N-phenyl-N′-isopropylp-phenylenediamine

We have previously reported the results of studies of the hydrogen bond nature in N-phenyl-N′-isopropyl-p-phenylenediamine by a quantum chemistry method and FTIR spectroscopy [1–3]. It is shown that the IR spectrum of N-phenyl-N′-isopropyl-p-phenylenediamine has IR bands in the vNH absorption region at 3380 cm⁻¹ and 3400 cm⁻¹ corresponding to the NH groups involved in hydrogen bonding.     

Synthesis of Potentially Bioactive Heterocycles: Thermal [3,3]Sigmatropic Rearrangement of 4‐(4′‐Aryloxybut‐2′‐ynyloxy)‐6‐methyl‐2‐pyridone

Synthesis of a number of hitherto unreported 4‐aryloxymethylene‐7‐methyl‐2,3‐dihydropyrano[3,2‐c]pyridine‐5‐ones 4a–h have been achieved in moderate yields by the thermal [3,3]sigmatropic rearrangement of 4‐(4′‐aryloxybut‐2′‐ynyloxy)‐6‐methyl‐2‐pyridone.     

Rapid Synthesis of 3‐Aminoimidazo[1,2‐a]Pyridines and Pyrazines

p‐Toluenesulfonic acid catalyzed the one‐pot, three‐component synthesis of 3‐aminoimidazo[1,2‐a]pyridines and pyrazines through a condensation reaction of a 2‐aminoazine, an aldehyde, and an isocyanide at room temperature. This methodology affords a number of 3‐aminoimidazo[1,2‐a]pyridines in reasonable yields and short reaction times without any significant optimization of the reaction conditions.     

Green Aspect for Multicomponent Synthesis of Spiro[4H-indeno[1,2-b]pyridine-4,3′-[3H]indoles]

An efficient, four-component reaction of isatin, 1,3-indanedione, ethyl acetoacetate, and ammonium acetate in ethanol/water (9:1) system furnished spiro[4H-indeno[1,2-b]pyridine-4,3′-[3H]indoles] at room temperature. Merits of the method are mild reaction conditions, simple workup procedure, and ambient temperature. The synthesized compounds exhibit excellent fluorescence properties.     

The application of copolymer-coated graphene oxide-Fe3O4 in the highly efficient synthesis of 2′-aminospiro[indeno[1,2-b]quinoxaline-11,4′-[4'H] pyran]-3′-carbonitrile and 2′-aminospiro[indeno-2,4′-[4'H]pyran]-3′-carbonitrile

A magnetic nanocomposite based on graphene oxide was prepared. Fe₃O₄ nanoparticles were loaded on graphene oxide sheets and GO-Fe₃O₄ was covered by aniline-pyrrole copolymer to afford poly(Py-co-Ani)@GO-Fe₃O₄. This nanocomposite was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, vibrating sample magnetometry, X-ray diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy techniques, and its catalytic activity was evaluated in the multicomponent synthesis of 2′-aminospiro[indeno[1,2-b]quinoxaline-11,4′-[4'H]pyran]-3′-carbonitrile and 2′-aminospiro[indeno-2,4′-[4'H]pyran]-3′-carbonitrile derivatives. This magnetically separable catalyst is heterogeneous noncorrosive, highly efficient, and reusable.     

Disordered Crystal Structure of 4,7,13,16,21,24‐hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacozane perchlorate

Crystals of the ionic complex (salt) of 4,7,13,16,21,24hexaoxa 1,10diazabicyclo[8.8.8]hexacozane perchlorate, [H₂(Crypt2.2.2)]²⁺ · 2ClO₄ ^-, were synthesized and studied by Xray structural analysis: space group C2/c, a = 20.198(3), b = 10.119(2), c = 12.938(2), = 90.97(1)°, Z = 4, 3030 measured independent reflections, R = 0.067. In these crystals, all atoms of the 2.2.2 dication are disordered over two positions with occupancies of 0.518(4) and 0.482(4). Two conformations of the disordered 2.2.2 dication are such that two H atoms at two nodal N atoms point to its cavity.     

Crystal structure of 4,4″-dinitro-[3,3′,4′,3″]-tris-[1,2,5]-oxadiazole

The crystal structure of a new energetic compound of 4,4″-dinitro-[3,3′:4,3″]-tris-[1,2,5]-oxadiazole is studied.     

Design and Syntheses of Novel Calix[4]crown: Calix[4]‐Dixanthates‐Crowns

Abstract

A series of novel calix[4]‐dixanthates‐crowns were designed and synthesized by the “1 + 1 condensation” of reacting calix[4]‐1,3‐dixanthate salts derivative (4) with polyethylene glycol ditosylates in 40–60% yields. It was found that the new calixcrowns showed outstanding complexation abilities towards soft cations. Calix[4]‐dixanthate‐crown‐4 (5b) exhibited high complexation selectivity towards Ni²⁺.     

Synthesis of derivatives of the new heterocyclic system pyrimido[4′,5′:4,5]pyrimido[1,2-a]benzimidazole

3-Phenyl-5-methyl(phenyl)-1H,3H-pyrimido[4,5:4,5]pyrimido[1,2-a]benzimi-dazole-2,4-diones were obtained by the cyclization of N-phenyl-N-[3-ethoxycar-bonyl-4-methyl(phenyl)pyrimido [1,2-a]benzimidazol-2-yl]ureas by the action of potassium carbonate. 2-Methyl-5-phenyl-1H-pyrimido[4,5:4,5]pyrimido[1,2-a]benzimidazol-4-one was obtained by the reaction of N-3-ethoxycarbonyl-4-phenylpyrimido[1,2-a]benzimidazol-2-yl]-N,N-dimethylacetamidine with ammonium acetate in ethanol. The synthesized compounds are members of a new heterocyclic system. The molecular and crystal structure of the solvate of 3-phenyl-5-methyl-1H,3H-pyrimido[4,5:4,5] pyrimido[1,2-a]benzimidazole-2,4-dione with two molecules of DMF was studied by x-ray crystallographic analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2587–2592, November, 1991.     

Crystal and molecular structure studies of 1′-Benzyl-8-(4-fluorobenzyl)-8-azaspiro[bicyclo-[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione

The title compound 1′-Benzyl-8-(4-fluorobenzyl)-8-azaspiro[bicyclo[3.2.1] octane-3,4′-imidazolidine]-2′,5′-dione, C₂₃H₂₃FN₃O₂ is synthesized and the structure is investigated by X-ray diffraction studies. The compound crystallizes in the triclinic crystal class in the P1 space group. The hydantoin ring adopts a planar conformation and is affected by the π conjugation. The pyrrolidine and piperidine rings in the bicyclo octane moiety adopt envelope and chair conformations respectively. The structure exhibits both inter- and intramolecular hydrogen bonds of the type N-H...O, C-H...O, and C-H...N. The oxygen atom in the hydantoin ring simultaneously accepts two hydrogen bonds to form a three-centered hydrogen bonding pattern.     

Glycosylation of 4‐Aryl‐1‐thioxo[1,2,4] triazolo[4,3‐a] quinazolin‐5(4H)‐one

Reaction of 4‐aryl‐1‐thioxo [1,2,4] triazolo [4,3‐a] quinazolin‐5 (4H)‐ones (2a,b) with acetylated glycosyl bromides 3a–c under alkaline conditions afforded the corresponding S‐glycoside derivatives 4, 5 and N‐glycoside derivatives 6, 7. Oxidation of S‐glycosyl derivatives 4, 5 with m‐chloroperbenzoic acid yielded the corresponding sulphones 8, 9, whereas the N‐glycosyl derivatives 6, 7 yielded 1‐oxo derivatives 10, 11. However their O‐deacetylation with sodium methoxide in methanol caused cleavage of the S‐glycosyl residue and gave N ²‐glycosylated analogues 12, 13, 14 and 15.     

Synthesis of 4′H-spiro[adamantane-2,3′-isoquinoline] derivatives

Russian Journal of Organic Chemistry -     

Synthesis and Crystal Structure of Spiro[1-bromo-4-methoxy-5-oxa-6-oxo-bicyclo[3.1.0]hexane-2,2′-（3′- cyclohexanoxy-4′-methoxybutyrolactone]

1INTRODUCTIONThecyclopropane-containingnaturalproductshavereceivedconsiderableattentionassynthetictar-getsastheincorporationofrigidifiedcyclopropylmotifintobioactiveanaloguescanleadtoconfor-mablyconstrainedmolecules[1,.Suchmodifica-2]tionsareexpectedtohavesignificanteffectsonbio-activitieswithconcomitantmedicalimplications.Des-pitethegreatadvancesinthisfield,theefficientsyn-thesisofspiro-cyclopropanecompoundsstillremainsaconsiderablechallenge.Particularnoticeisthede-ficiencyinthepreviousm…     

Dipyrrolo[1,2-a; 2′,1′-c]pyrazines. 4. Aminomethylation of alkyl substituted dipyrrolo[1,2-a; 2′,1′-c]pyrazines and 5,6-dihydrodipyrrolo[1,2-a; 2′,1′-c]pyrazines

We have studied the aminomethylation reaction of alkyl substituted dipyrrolo[1,2-a; 2,1-c]pyrazines and their 5,6-dihydro analogs using different aminomethylating agents. Use of alkoxydialkylaminomethanes (aminoacetals) as Mannich reagents leads to the highest yields of the aminomethylated dipyrrolopyrazines. The compounds prepared have been studied by mass spectrometry.For Communication 3, see [1].M. V. Lomonosov State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–957, July, 1998.     

Crystal Structure and Antitumor Activity of Tri[2-[N-（4′-methyl-benzylsulfonyl）amino]ethyl]-amine

The crystal structure of the title compound (C27H38N4O7S3, Mr = 626.79) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group Pīwith a = 9.411(1), b = 11.645(2), c = 14.672(2) (A。), α = 91.80(1), β = 95.36(1), γ =104.56(1)o, V = 1547.0 (A。)3, Z = 2, Dc = 1.346 g/cm3, λ = 0.71073 (A。), μ(MoKα) = 0.289 mm－1 and F(000) = 664. The structure was refined to R = 0.0406 and wR = 0.1177 for 4103 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the title compound is a practically distorted tetrahedron and each molecule contains one lattice H2O by hydrogen bond. The antitumor activity of the title compound against HL-60 human leukemia cells has also been studied by MTT method.     

Synthesis of Some Novel bis‐Spiro[indole‐pyrazolinyl‐thiazolidine]‐2,4′‐diones

The reaction of 1H‐indol‐2,3‐diones with 1,6‐dibromohexane has resulted in the formation of new 1H‐indol‐2,3‐diones‐1,1′‐(1,6‐hexanediyl)bis in quantitative yields. These compounds have been used for the synthesis of novel [3′‐(2,3‐dimethyl‐5‐oxo‐1‐phenyl‐3‐pyrazolin‐4‐yl)spiro[3H‐indol‐3,2′‐thiazolidine]‐2,4′‐dione]‐1,1′‐(1,6‐hexanediyl)bis via bis Schiff's bases, [3‐(2,3‐dimethyl‐5‐oxo‐1‐phenyl‐3‐pyrazolin‐4‐yl) imino‐1H‐indol‐2‐one]‐1,1′‐(1,6‐hexanediyl)bis.     

Synthesis of 3‐Aryl‐5‐methyl 4‐Substituted [1,2,4]Triazoles

Treatment of N‐substituted acetamides with oxalyl chloride generates imidoyl chlorides, which react readily with aryl hydrazides. Following cyclization, triazoles can easily be obtained in moderate to good yields. 5‐Methyl triazoles can be further functionalized through α‐lithiation and subsequent reaction with an electrophile.     

Synthesis of 4′-alkyl-8-azaspiro[bicyclo[3.2.1]octane-3,2′-morpholin]-5′-ones

N-Boc-protected 8-azaspiro[bicyclo[3.2.1]octane-3,2′-oxirane] reacted with primary aliphatic amines through opening of the epoxide ring with formation of the corresponding amino alcohols which were converted into N-chloroacetyl derivatives. The latter underwent cyclization to N-Boc-protected 4′-alkyl-8-azaspiro[bicyclo[3.2.1]octane-3,2′-morpholin]-5′-ones by the action of sodium hydride in DMF, and subsequent treatment with hydrogen chloride in ethyl acetate afforded 8-azaspiro[bicyclo[3.2.1]octane-3,2′-morpholin]-5′-one hydrochlorides.