Showing papers on "Morpholine published in 2002"

The formation of paracetamol (acetaminophen) adducts with hydrogen-bond acceptors

Abstract: The crystal structures of five hemiadducts of paracetamol with 1,4-dioxane, N-methylmorpholine, morpholine, N,N-dimethylpiperazine and piperazine and a related 1:1 adduct of paracetamol with 4,4′-bipyridine are described. All structures are characterized by the formation of chains of paracetamol molecules, which are linked via either OH⋯O=C interactions [C(9) chains in graph-set notation] or NH⋯O=C interactions [C(4) chains], depending on the presence or absence of substituent groups on the guest molecule. In all cases except for the morpholine and bipyridine adducts these chains are connected by hydrogen-bond interactions with the guest molecules, which reside on crystallographic inversion centres. In the bipyridine adduct this linkage also involves a π-stacking interaction; in the morpholine adduct it is formed between the OH groups of two opposed paracetamol molecules. Most adducts (that with 4,4′-bipyridine is an exception) decompose on heating to give monoclinic paracetamol. This is the first systematic study of a series of co-crystals containing paracetamol.

New enamine derivatives of lapachol and biological activity

Abstract: A convenient synthesis of the new enamine derivatives 2-(4-morpholinyl)-3-(3-methyl-2-butenyl)-1,4-naphthalenedione, 2-(1-piperidinyl)-3-(3-methyl-2-butenyl)-1,4-naphtalenedione and 2-(1-pyrrolidinyl)-3-(3-methyl-2-butenyl)-1,4-naphthalenedione was carried out from natural 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthalenedione (lapachol) and morpholine, piperidine and pyrrolidine. The structures of the products were established mainly by NMR analysis, including 2D experiments. Biological activities of these products were evaluated against Artemia salina, Aedes aegypti and cytotoxicity using A549 human breast cells.

Addition of organocerium reagents to morpholine amides: synthesis of important pheromone components of Achaea janata.

Abstract: Readily preparable morpholine amides hitch in good yields with organocerium reagents to produce ketones. Even in the presence of substrates and reagents with high steric hindrance, the organometallic compounds prepared from dry cerium(III) chloride and organomagnesium or organolithium compounds at -78 degrees C add cleanly to morpholine amides. The low cost of starting materials makes this new scheme of synthesis very interesting for the preparation of biologically important pheromones.

A Modified Synthesis of Iodoazidoaryl Prazosin

Abstract: The antihypertension agent iodoazidoaryl prazosin (IAAP) has been made using a convergent route involving addition of an acylated piperazine 7 to 2-chloroquinazoline 5. IAAP has been shown to function as a multidrug resistance (MDR) reversal agent and bind to P-glycoprotein, a transmembrane transport protein. A study is also reported involving palladium-catalyzed substitution with amine heterocycles. With N,N-bis(2,6-diisopropyl)dihydroimidazolium chloride (10) as the ligand (2 mol %) for palladium(II) acetate (2 mol %) in THF at room temperature, morpholine added to 5 in 81% yield.

An unexpected equilibrium process associated with a standard approach to ynone synthesis.

Abstract: A direct comparison between Weinreb amides and morpholine amides was made with regard to their reactions with alkynyllithium reagents to form ynones. While treatment with stoichiometric alkynyllithium generally effects complete reaction in the case of Weinreb amides, incomplete reactions are obtained from the corresponding morpholine amides. This difference is attributed to an unexpected equilibrium process in the latter case, and it is shown that the use of excess alkynyllithium reagent with morpholine amides provides a synthetically useful synthesis of ynones at 0 °C.

Synthesis of Bis(2,4-diarylimidazol-5-yl) Diselenides from N-Benzylbenzimidoyl Isoselenocyanates

Abstract: The reaction of N-benzylbenzamides 6 with SOCl2 under reflux gave the corresponding N-benzylbenzimidoyl chlorides 7. Further treatment with KSeCN in dry acetone yielded imidoyl isoselenocyanates 3 (Scheme 2). These compounds, obtained in satisfying yields, proved to be stable enough to be purified and analyzed. Reaction of 3 with morpholine in dry acetone led to the corresponding selenourea derivatives 8. On treatment with Et3N, the 4-nitrobenzyl derivatives of type 3 were transformed into bis(2,4-diarylimidazol-5-yl) diselenides 9 (Scheme 3). This transformation takes place only when the benzyl residue bears an NO2 group and the phenyl group is not substituted with a strong electron-donating group. A reaction mechanism for the formation of 9 is proposed in Scheme 4. The key structures have been established by X-ray crystallography.

Effects of geometrical difference of unsaturated aliphatic polyesters on their biodegradability II. Isomerization of poly(maleic anhydride-co-propylene oxide) in the presence of morpholine

Abstract: Ring-opening copolymerizations of succinic anhydride (SAn, 1) or maleic anhydride (MAn, 2) with propylene oxide (PO) were carried out by using magnesium diethoxide (Mg(OEt)2) as a catalyst. The unsaturated polyester (P2a) was found to have only Z-configuration around a C=C double bond from its 1H and 13C NMR spectra. Isomerization reaction of P2a from Z- to E-configuration was performed in 1,2-dichloroethane with a catalytic amount of morpholine. Thus unsaturated polyesters, P2b-e, having the same molecular weight but the different ratio of Z-/E-configuration could be optionally prepared from one original polymer P2a by controlling isomerization reaction time. Biodegradability of these polyester samples was evaluated from their biochemical oxygen demand (BOD) values in the presence of an activated sludge. Polyester P2a was hardly degraded during measurement. However, polyesters P2b-e, partially containing E-configuration of the C=C double bond, degraded considerably faster than P2a itself. The biodegradability of saturated polyester P1 was also examined to compare with the P2-series.

A practical variant of the Claisen-Eschenmoser rearrangement: Synthesis of unsaturated morpholine amides

Abstract: A Claisen-Eschenmoser type rearrangement giving rise to unsaturated morpholine-, piperidine- and pyrrolidine amides is described.

Ferrocene-1,1′-dicarboxylic acid as a building block in supramolecular chemistry: supramolecular structures in one, two and three dimensions

Abstract: The supramolecular structures have been determined for nine adducts formed between organic diamines and ferrocene-1,1′-dicarboxylic acid. In the salt-like 1:1 adduct (1) formed with methylamine, the supramolecular structure is one-dimensional, whereas in the 1:1 adducts formed with 1,4-diazabi­cyclo[2.2.2]octane, (2), and 4,4′-bipyridyl, (4), and in the hydrated 2:1 adduct (3) formed with morpholine, the hard hydrogen bonds form one-dimensional structures, which are expanded to two dimensions by soft C—H⋯O hydrogen bonds. The hard hydrogen bonds generate two-dimensional structures in the 2:1 adduct (5) formed with octylamine, where the ferrocene component lies across a centre of inversion, in the 1:1 adduct (6) formed with piperidine and in the tetra­hydrofuran-solvated 1:1 adduct (7) formed with di(cyclo­hexyl)amine. In the 2:3 adduct (8) formed by tris-(2-aminoethyl)amine, and in the 2:1 adduct (9) formed with 2-(4′-hydroxyphenyl)ethylamine (tyramine), where Z′ = 1.5 in space group P\bar{1}, the hard hydrogen bonds generate three-dimensional structures. No H transfer from O to N occurs in (4) and only partial transfer of H occurs in (2); in (1), (6) and (7), one H is transferred to N from each acid molecule, and in (3), (5), (8) and (9), two H are transferred from each acid molecule.

Synthesis, structure, and electrochemistry of cobalt(III) complexes with bis(benzoylacetone)ethylenediimine Schiff base

Abstract: A series of complexes of the type trans-[Co((BA)2en)(amine)2]ClO4 — where (BA)2en is the bis(benzoylacetone)ethylenediimine dianion and the amines are morpholine (mrpln) 1, aniline (aniln) 2, benzylamine (bzlan) 3, piperidine (pprdn) 4, p-toluidine (p-toldn) 5, and pyrrolidine (prldn) 6 — has been synthesized and characterized by elemental analysis, UV–vis, 1H NMR, and 13C NMR spectroscopy. The crystal and molecular structure of trans-[Co((BA)2en)(mrpln)2]ClO4 (1) has been determined by X-ray crystallography. The electrochemical reduction of these complexes at a glassy-carbon electrode, in the potential range of 0.5 to –2.0 V (vs. Ag/AgCl), in acetonitrile solution, indicates that the first reduction potential of Co(III/II) is irreversible, which is accompanied by the dissociation of the axial amine–cobalt bonds. This potential is dependent on the pKa of the axial amines. The second reduction potential of Co(II/I) shows reversible behavior and is also independent of the axial amine pKa. These results indi...

Highly sulfurated heterocycles via dithiiranes and trithietanes as key intermediates.

Abstract: 2,2,4,4-Tetramethyl-3-thioxocyclobutanone (8b) easily reacts with gaseous chlorine to yield the stable α-chloro sulfenyl chloride 10. The same product was obtained when 8b was treated either with phosphorus pentachloride (PCl5) or sulfuryl chloride (SO2Cl2) in CCl4 solution. Sulfur dichloride (SCl2) reacts with 8b to give the α-chloro thiosulfenyl chloride 12 along with an almost equimolar amount of the trisulfide 13b. The less reactive disulfur dichloride (S2Cl2) was shown to react slowly with 8b and the symmetrical tetrasulfide 15 was found as the exclusive product. The pure thiosulfenyl chloride 12 added to adamantanethione (8c) yielded the unsymmetrical trisulfide 13c. When 12 was treated with thioacetic acid, the acetylated trisulfide 17 was formed in high yield. “Unzipping” reactions with the acetylated disulfide 16 and trisulfide 17 with morpholine in THF at −40 °C led to the formation of mixtures of two sulfur-rich heterocycles identified as the pentathiepane 6b and the hexathiepane 7b. A mixture ...

Instabilities in the System NMMO/Water/Cellulose (Lyocell Process) Caused by Polonowski Type Reactions

Abstract: Polonowski type degradation reactions arc a major reason for the frequently observed instability of solutions of cellulose in N-methylmorpholine-N-oxide monohydrate (NMMO. 1). The degradation is induced by degradation products of cellulose and NMMO generated in situ in the Lyocell system. The presence of both an amine component such as morpholine or N-methylmorpholine, and an acid component is required for the decomposition process to proceed. The latter might be a low-molecular-weight compound, such as formic acid, acetic acid or gluconic acid, or also a high-molecular-weight acid, such as polyglucuronic acid or ion exchange resin.

Piezoelectric chemical sensors based on morpholine containing polymers

Abstract: A Quartz Crystal Microbalance, QCM, based system has been developed for the selective analysis of Cu 2+ ions in aqueous solution. The crystal is coated with a thin film of poly(acryloyl morpholine) which selectively chelates Cu 2+ over other M 2+ ions. A novel coating procedure involving the preparation of sulphur terminated polymer chains followed by self-assembly onto the gold was used. The sensor could be used over the concentration range between 0.5 – 70 ppm. The method shows promise although further optimisation of the coating procedures and ligand loading are needed to extend the concentration range and improve the speed of response.

Kinetic and mechanistic investigation of the aminolysis of 3-methoxyphenyl 3-nitrophenyl thionocarbonate, 3-chlorophenyl 3-nitrophenyl thionocarbonate, and bis(3-nitrophenyl) thionocarbonate.

Abstract: The reactions of the title thionocarbonates (6, 7, and 8, respectively) with a series of secondary alicyclic amines are subjected to a kinetic investigation in 44 wt % ethanol−water, 25.0 °C, ionic strength 0.2 M (KCl). Under excess amine, pseudo-first-order rate coefficients (kobsd) are obtained for all reactions. Reactions of substrates 6 and 7 with piperidine and of thionocarbonate 8 with the same amine and piperazine, 1-(2-hydroxyethyl)piperazine, and morpholine show linear kobsd vs [amine] plots, with slopes (k1) independent of pH. On the other hand, these plots are nonlinear upward for the reactions of substrates 6 and 7 with all the amines, except piperidine, and also for the reactions of compound 8 with 1-formylpiperazine and piperazinium ion. For all these reactions a mechanistic scheme is proposed with the formation of a zwitterionic tetrahedral intermediate (T±), which can transfer a proton to an amine to give an anionic intermediate (T-). Rate and equilibrium microcoefficients of this scheme, ...

C-phosphorylation of 1,2,4-triazoles with phosphorus(III) halides. Synthesis of 4,5-dihydrobenzo[e][1,2,4]triazolo[5,1-c][1,4,2]diazaphosphinine derivatives

Abstract: Phosphorylation of 4- and 1-substituted 1,2,4-triazoles with PCl3, PhPCl2, Ph2PCl, and (Et2N)2 PCl was carried out. A novel phosphorus-containing condensed heterocyclic system (18, 23) was constructed by the reactions of 2-(1H-1,2,4-triazol-1-yl)-1-(4-chlorophenylcarboxamido)-5-trifluoromethylbenzene with PBr3 and PhPBr2. Treatment of the bromophosphonite 18 with an excess of morpholine in the presence of sulfur resulted in a diazaphosphinine ring opening and provided functionalized 1H-1,2,4-triazol-5-ylphosphonic acid derivatives 21 and 22. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:146–152, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10010

Amine carboxylates as vapour phase corrosion inhibitors

Abstract: Fifty three products, mostly carboxylate salts of amines, were evaluated as vapour phase corrosion inhibitors for mild steel. Fifteen compounds showed effectiveness in excess of 90%. Morpholine was the most effective amine and caprylic acid the most effective acid constituent. The effectiveness of ammonium monocarboxylates decreased with increase in the length of the carbon chain of the carboxylic acid. The other carboxylates did not show such a clear trend.

The oxidation of fullerenes (C 60 , C 70 ) with various oxidants under ultrasonication

Abstract: The reaction of C60, under ultrasonication, with various oxidants, such as 3-chloroperoxy benzoic acid (Fluka 99%), 4-methyl morpholine N-oxide (Aldrich 97%), chromium (VI) oxide (Aldrich 99.9%), and the oxone® monopersulfate compound, causes the oxidation of fullerenes at room temperature. The FAB-MS spectra and HPLC profile confirmed that the products of fullerene oxidation were [C60(O)n] (n=1∼3 or n=1). C70 also reacted, under ultrasonication, with various oxidants, but the reaction rate of C70 was lower than that of C60.

Preparation, spectral characterization, in vitro antitumor and thermal studies of new platinum(IV) and palladium(II) thiohydrazone complexes

Abstract: PtIV and PdII complexes [Pt(L)2Cl2] and [Pd(HL)Cl2] [HL = salicyclaldehyde morpholine N-thiohydrazone (HL1), benzaldehyde morpholine N-thiohydrazone (HL2), acetophenone morpholine N-thiohydrazone (HL3), p-methylacetophenone morpholine N-thiohydrazone (HL4), cinnamaldehyde morpholine N-thiohydrazone (HL5), cyclohexanone morpholine N-thiohydrazone (HL6), benzaldehyde aniline N-thiohydrazone (HL7), benzaldehyde N-(methyl, cyclohexyl)-thiohydrazone (HL8) and benzaldehyde N-(ethyl, cyclohexyl)-thiohydrazone (HL9)] were prepared in MeOH and characterized by elemental analysis, i.r., electronic, 1H-n.m.r. and 13C-n.m.r. spectral data. For some of the complexes cyclic voltammetric and thermal studies were carried out. The in vitro antitumor activity of some complexes was measured.

Dianionic complexes with hexacoordinate silicon(IV) or germanium(IV) and three bidentate ligands of the salicylato(2–) type: Syntheses and structural characterization in the solid state and in solution

Abstract: Reaction of tetramethoxysilane or tetramethoxygermane with salicylic acid and morpholine (molar ratio 1:3:2) in tetrahydrofuran yielded morpholiniummer-tris[salicylato(2–)-O1,O3]silicate(mer -5) and morpholiniummer-tris[salicylato(2–)-O1,O3]germanate (mer-8), respectively. Treatment of tetramethoxysilane with 5-chlorosalicylic acid and piperidine (molar ratio 1:3:2) in tetrahydrofuran afforded piperidinium mer-tris[5-chlorosalicylato(2–)-O1,O3]silicate–ditetrahydrofuran (mer-6·2THF). Triethylammonium mer-tris[3-methylsalicylato(2–)-O1,O3]silicate (mer-7) was obtained analogously by reaction of tetramethoxysilane with three molar equivalents of 3-methylsalicylic acid and two molar equivalents of triethylamine in dichloromethane/diethyl ether. The racemic compounds mer-5, mer-6· 2THF,mer-7, and mer-8 were characterized by elemental analyses (C, H, N), single-crystal X-ray diffraction, as well as solid-state (29Si) and solution(1H, 13C, 29Si) NMR studies. The structural characterizationwas complemented by computational studies (HF studies, TZVP level) of thefac- and mer-tris[salicylato(2–)-O1,O3]silicatedianion. In addition, the behavior of mer-7 in solution was studied by VT 1HNMR experiments.

Linear free energy ortho-correlations in the reactions of some 2-bromo-5-nitro-3-X-thiophenes with primary and secondary amines in benzene

Abstract: The kinetics of SNAr reactions of some 2-bromo-3-X-5-nitrothiophenes (X = Me, H, Br, CONH2, CO2Me, COMe, SO2Me, CN and NO2) with some primary (n-butylamine and benzylamine) and secondary (pyrrolidine, piperidine, morpholine and N-benzylamine) amines have been measured in benzene as a function of nucleophile concentration. Most of the reactions studied show apparent kinetic constants little affected or not affected by an increase in amine concentration, indicating that the overall reaction rate is controlled by the formation of the reaction intermediate. The reactions of the substrates where X = Br and CN with the two primary amines proved to be base-catalysed. The k3B/k−1 values calculated for these substituents are inconsistent with the hypothesis of a base catalysis for the intermediate decomposition and strongly suggest a catalysis of the first step of the reaction pathway.

The hexacoordinate silicate dianions mer-tris[glycolato(2-)-O(1),O(2)]silicate and fac-tris[benzilato(2-)-O(1),O(2)]silicate: syntheses and structural characterization.

Abstract: Treatment of tetramethoxysilane with glycolic acid and morpholine (molar ratio 1:3:2) in methanol, followed by crystallization from methanol/tetrahydrofuran, yielded morpholinium mer-tris[glycolato(2−)-O1,O2]silicate (mer-7). Treatment of benzilic acid with sodium hydride, followed by addition of tetrachlorosilane and triethylamine (molar ratio 3:4:1:2), afforded, after crystallization from 1,4-dioxane/acetonitrile/diethyl ether/n-pentane, triethylammonium fac-tris[benzilato(2−)-O1,O2]silicate−hemi-1,4-dioxane (fac-8·1/2C4H8O2). Single-crystal X-ray diffraction studies showed that the Si-coordination polyhedra of the hexacoordinate silicon(IV) complexes mer-7 and fac-8·1/2C4H8O2 are distorted octahedra. Both compounds were additionally characterized by solid-state VACP/MAS NMR studies (13C, 29Si), and fac-8·1/2C4H8O2 was studied in solution by 1H, 13C, and 29Si NMR experiments. The structural investigations were complemented by computational studies (MP2 studies, TZP level) of the dianions of fac-7 and mer-7.