Showing papers on "Morpholine published in 2000"
TL;DR: A catalytic system for the mild amination of aryl chlorides is described, which consists of a Pd(0) precursor and a dihydroimidazoline carbene ligand generated in situ from its protonated tetrafluoroborate salt.
276 citations
TL;DR: This reaction provides an efficient route to the second generation NNRTI drug candidate DPC 963 by using enantiopure amino alcohol as a chiral moderator for the addition of lithium cyclopropylacetylide to an unprotected N-acylketimine.
162 citations
TL;DR: In this paper, the adjustment of the water content of the catalytic solid and the addition of a cationic surfactant (CTAB) in the medium both contribute to improve drastically the efficiency of the catalyst while keeping the palladium leaching below 0.5%.
Abstract: The high surface hydrophilicity of chitosan is the property which has allowed the synthesis of an efficient, selective, and stable palladium supported aqueous phase catalyst for the reaction of allylic substitution of (E)-cinnamyl ethyl carbonate by morpholine. The adjustment of the water content of the catalytic solid and the addition of a cationic surfactant (CTAB) in the medium both contribute to improve drastically the efficiency of the catalyst while keeping the palladium leaching below 0.5%.
140 citations
TL;DR: A free radical mechanism is proposed, involving one-electron oxidation by peroxynitrite of secondary amines to form amino radicals (R(2)N(*)), which react with nitric oxide or nitrogen dioxide to yield nitroso and nitrosecondary amines, respectively.
Abstract: Reactive nitrogen species, including nitrogen oxides (N(2)O(3) and N(2)O(4)), peroxynitrite (ONOO(-)), and nitryl chloride (NO(2)Cl), have been implicated as causes of inflammation and cancer. We studied reactions of secondary amines with peroxynitrite and found that both N-nitrosamines and N-nitramines were formed. Morpholine was more easily nitrosated by peroxynitrite at alkaline pH than at neutral pH, whereas its nitration by peroxynitrite was optimal at pH 8.5. The yield of nitrosomorpholine in this reaction was 3 times higher than that of nitromorpholine at alkaline pH, whereas 2 times more nitromorpholine than nitrosomorpholine was formed at pH <7.5. For the morpholine-peroxynitrite reaction, nitration was enhanced by low concentrations of bicarbonate, but was inhibited by excess bicarbonate. Nitrosation was inhibited by excess bicarbonate. On this basis, we propose a free radical mechanism, involving one-electron oxidation by peroxynitrite of secondary amines to form amino radicals (R(2)N(*)), which react with nitric oxide ((*)NO) or nitrogen dioxide ((*)NO(2)) to yield nitroso and nitro secondary amines, respectively. Reaction of morpholine with NO(*) and superoxide anion (O(2)(*)(-)), which were concomitantly produced from spermine NONOate and by the xanthine oxidase systems, respectively, also yielded nitromorpholine, but its yield was <1% of that of nitrosomorpholine. NO(*) alone increased the extent of nitrosomorpholine formation in a dose-dependent manner, and concomitant production of O(2)(*)(-) inhibited its formation. Reactions of morpholine with nitrite plus HOCl or nitrite plus H(2)O(2), with or without addition of myeloperoxidase or horseradish peroxidase, also yielded nitration and nitrosation products, in yields that depended on the reactants. Tyrosine was nitrated easily by synthetic peroxynitrite, by NaNO(2) plus H(2)O(2) with myeloperoxidase, and by NaNO(2) plus H(2)O(2) under acidic conditions. Nitrated secondary amines, e.g., N-nitroproline, could be identified as specific markers for endogenous nitration mediated by reactive nitrogen species.
96 citations
TL;DR: In this article, a new method for the synthesis of N -protected α-amino aldehydes was developed, which can be used with Boc, Z and Fmoc amino-protecting groups.
61 citations
TL;DR: In this article, the rhodium catalysed hydroaminomethylation of the unsaturated fatty acid derivatives oleic acid ethyl ester (1) and oleyl alcohol (2) with the primary amines hexylamine (3), benzylamine, aspartic acid diethyl esters (5) and valinol (6), and with the secondary amine morpholine (7), respectively, proceeds with good to excellent yields.
Abstract: The rhodium catalysed hydroaminomethylation of the unsaturated fatty acid derivatives oleic acid ethyl ester (1) and oleyl alcohol (2) with the primary amines hexylamine (3), benzylamine (4), aspartic acid diethyl ester (5) and valinol (6), and with the secondary amine morpholine (7), respectively, proceeds with good to excellent yields. Using primary amines the structure of the reaction products depends on the stoichiometry of the reactants. Performing the reaction of (1) with (3) with an excess of the amine compound the corresponding secondary amine (9) (1:1-adduct) was observed. Working with a 2-fold excess of (1) the tertiary amine (16) (2:1-adduct) was the main product.
60 citations
TL;DR: A series of 3-aryl-1,6-naphthyridine-2,7-diamines and related 2-ureas were prepared and evaluated as inhibitors of the FGF receptor-1 tyrosine kinase and showed significant in vivo antitumor effects in a highly vascularized mammary adenocarcinoma 16/c model at nontoxic doses.
Abstract: A series of 3-aryl-1,6-naphthyridine-2,7-diamines and related 2-ureas were prepared and evaluated as inhibitors of the FGF receptor-1 tyrosine kinase. Condensation of 4,6-diaminonicotinaldehyde and substituted phenylacetonitriles gave intermediate naphthyridine-2,7-diamines, and direct reaction of the monoanion of these (NaH/DMF) with alkyl or aryl isocyanates selectively gave the 2-ureas in varying yields (23−93%). For the preparation of more soluble 7-alkylamino-2-ureas, a number of protecting groups for the 2-amine were evaluated (phthaloyl, 4-methoxybenzyl) following selective blocking of the 7-amine (trityl), but these were not superior to the (required) 2-tert-Bu-urea group itself. Direct alkylation of the anion of the (unprotected) 7-amino group with excess 4-(3-chloropropyl)morpholine in DMF gave low (10%) yields of the desired product, but alkylation of the 7-acetamido anion, followed by mild alkaline hydrolysis, raised this to 64%. 3-Phenyl analogues were nonspecific inhibitors of isolated c-Src...
57 citations
TL;DR: The enzymatic ring-opening polymerization of 6-membered cyclic depsipeptides, 3(S)-isopropyl-morpholine-2,5-dione, and 6(R,S)-methyl- Morpholine-1,4-diones in the bulk were investigated by using the lipase PPL as a catalyst, indicating that the present polymerization proceeds throughenzymatic catalysis.
Abstract: The enzymatic ring-opening polymerization of 6-membered cyclic depsipeptides, 3(S)-isopropyl-morpholine-2,5-dione, 3(R)-isopropyl-morpholine-2,5-dione, 3(R,S)-isopropyl-morpholine-2,5-dione, (3S, 6R, S)-3-isopropyl-6-methyl-morpholine-2,5-dione, 3(S)-isobutyl-morpholine-2,5-dione, 3(S)-sec-butyl-morpholine-2,5-dione, 6(S)-methyl-morpholine-2,5-dione, and 6(R,S)-methyl-morpholine-2,5-dione in the bulk, was investigated by using the lipase PPL as a catalyst. In the absence of the enzyme, the monomers were recovered, indicating that the present polymerization proceeds through enzymatic catalysis. During the polymerization of morpholine-2,5-diones racemization of both the amino acid and the S-lactic acid moiety takes place. Enzymatic polymerization produces polydepsipeptides with a carboxylic acid group at one end and a hydroxyl group at the other one.
51 citations
TL;DR: In this article, a rotational barrier of ΔG⧧(CN-rot) = 12.1 ± 0.2 kcal mol-1 was measured for meso-4b in solution by dynamic 600 MHz 1H NMR spectroscopy.
48 citations
TL;DR: In this paper, it was shown that both nitration and nitrosation by peroxynitrite are free radical processes, and the morpholine radical (Mor•), formed from the reactions of carbonate and/or hydroxyl radicals with MorH, reacts with either •NO or •NO2 and serves as a common precursor for morpholine and Mor-NO2.
Abstract: Peroxynitrite reacts with morpholine (MorH) to give both N-nitromorpholine (Mor-NO2) and N-nitrosomorpholine (Mor-NO). The pH profile of Mor-NO2 formation shows a bell-shaped curve with a maximum yield of 1.6 mol % (relative to peroxynitrite) centered around pH 9.0. Yields of Mor-NO, on the other hand, increase until the pH reaches 10.0 and then reach a plateau; the maximum yield of Mor-NO is 12 mol % relative to peroxynitrite. Both the nitration and nitrosation of MorH are catalyzed by low levels of CO2; however, excess CO2 dramatically reduces the yields of Mor-NO but not Mor-NO2, and the combined yields of Mor-NO and Mor-NO2 are about the same under conditions of high and low concentrations of CO2. These data indicate that both nitration and nitrosation by peroxynitrite are free radical processes. The morpholine radical (Mor•), formed from the reactions of carbonate and/or hydroxyl radicals with MorH, reacts with either •NO or •NO2 and serves as a common precursor for Mor-NO and Mor-NO2.
46 citations
TL;DR: The surface concentration of N and P, determined by XPS, indicates that a concentration of 400 mM of the carrier in the casting solution is sufficient to saturate the surface of the membrane.
TL;DR: The degradation of piperidine by Mycobacterium aurumMO1 was investigated by performing H-nuclear magnetic resonance directly with the incubation medium and mass spectrometry confirmed the structure of some metabolites during morpholine and thiomorpholine degradation.
Abstract: In order to see if the biodegradative pathways for morpholine and thiomorpholine during degradation by Mycobacterium aurum MO1 could be generalized to other heterocyclic compounds, the degradation of piperidine by this strain was investigated by performing 1H-nuclear magnetic resonance directly with the incubation medium. Ionspray mass spectrometry, performed without purification of the samples, was also used to confirm the structure of some metabolites during morpholine and thiomorpholine degradation. The results obtained with these two techniques suggested a general pathway for degradation of nitrogen heterocyclic compounds by M. aurum MO1. The first step of the degradative pathway is cleavage of the C—N bond; this leads formation of an intermediary amino acid, which is followed by deamination and oxidation of this amino acid into a diacid. Except in the case of thiodiglycolate obtained from thiomorpholine degradation, the dicarboxylates are completely mineralized by the bacterial cells. A comparison with previously published data showed that this pathway could be a general pathway for degradation by other strains of members of the genus Mycobacterium.
TL;DR: In this article, a reaction mechanism via the initial formation of corresponding aroyl isoselenocyanates followed by a 1,3-dipolar cycloaddition of the diazo compound with the C=Se bond to give ethyl 5-(aroylimino)-4,5-dihydro-1,2,3 -selenadiazole-4-carboxylates of type D is proposed.
Abstract: The reaction of aroyl chlorides 1 with KSeCN and ethyl diazoacetate (6) in acetone at room temperature yields ethyl 2-aroyl-5-(aroylimino)-2,5-dihydro-1,2,3-selenadiazole-4-carboxylates 7 (Scheme 3). A reaction mechanism via the initial formation of the corresponding aroyl isoselenocyanates 2 followed by a 1,3-dipolar cycloaddition of the diazo compound with the C=Se bond to give ethyl 5-(aroylimino)-4,5-dihydro-1,2,3-selenadiazole-4-carboxylates of type D is proposed. Acylation of the latter at N(2) leads to the final products 7. Deacetylation of 7 to give ethyl 5-(aroylimino)-1,2,3-selenadiazole-4-carboxylates 10 is achieved by treatment of 7 with morpholine (Scheme 5). The intermediate isoselenocyanates 2 partially oligomerize to give two different oligomers. The symmetrical one reacts with morpholine to yield selenourea derivatives 12 (Scheme 6).
TL;DR: The high reactivity depicted by terminal ynamines in the Pauson-Khand reaction has been analyzed by theoretical semiempirical procedures and with density functional theory and appears to reflect an easy CO loss from the ynamine-dicobalt hexacarbonyl complexes.
Abstract: A family of dicobalt hexacarbonyl complexes of 1-(dialkylamino)-2-(trimethysilyl)acetylenes (3a−f) derived both from achiral and chiral amines [a, morpholine; b, (S)-2-methoxymethylpyrrolidine; c, (2R,5R)-2,5-bis(methoxymethyl)pyrrolidine; d, (±)-trans-2,5-bis(benzyloxymethyl)pyrrolidine; e, (2R,5R)-2,5-dimethylpyrrolidine; f, (S)-(α-methylbenzyl)benzylamine] has been prepared by a one-stage process from dichloroacetylene. The methanolysis at room temperature of these complexes (MeOH/K2CO3) induces the selective cleavage of the carbon−silicon bond, leading to the thermally unstable terminal ynamine complexes 12a−f. The Pauson−Khand reaction of 12a−f with strained olefins (norbornadiene and norbornene) takes place at unprecedentedly low temperatures (−35 °C) in the absence of chemical promoters. Diastereoselectivities of up to 94:6 are recorded in these reactions with the ynamine complexes derived from C2 symmetrical chiral auxiliaries (12c,d). The high reactivity depicted by terminal ynamines in the Pauso...
TL;DR: In this paper, the new cyclo-diboratetrasiloxanes (RBO)2(R′2SiO)2 (R=p-BrC6H4, o-MeC6C4, m-NH2C6h4; R′2=Me2, Ph/Me) were prepared in high yield by condensation reactions and the Lewis acidity of these borasiloxane rings was determined by the Gutmann's acceptor number (AN) method.
TL;DR: Tetradentate salicylaldimine ligands of the H2salen type bearing ortho-N-morpholinomethyl substituents function as ditopic ligands, bonding to NiII or CuII with the [N2O2]2− donor set of the salen unit and a sulfate or two nitrate anions with the protonated morpholine units as mentioned in this paper.
Abstract: Tetradentate salicylaldimine ligands of the H2salen-type bearing ortho-N-morpholinomethyl substituents function as ditopic ligands, bonding to NiII or CuII with the [N2O2]2− donor set of the salen unit and a sulfate or two nitrate anions with the protonated morpholine units. The binding of the metal salt by the zwitterionic form of the ligand provides a novel approach to the transport of metal sulfates in metal recovery processes. A comparison of the solid state structures of a “free” ligand with a series of nickel(II) complexes demonstrates that the metal ion templates the ligand system, orientating the pendant morpholinium groups to form electrostatic and bifurcated hydrogen bonds in the sulfate complex to the dianion creating a neutral 1∶1∶1 [LM2+X2−] complex suitable for extraction into water immiscible solvents. Other binding modes involving bridging of metal complex units by anion binding to the pendant morpholine groups suggest that these ditopic ligands could also be used to assemble unusual three-dimensional arrays of metal complexes in the solid state.
TL;DR: The inclusion of a C-2 trialkylsilyl substituent into allylic amine precursors allows the base-induced aza-[2,3]-Wittig sigmatropic rearrangement to proceed in excellent yield and diastereoselectivity as mentioned in this paper.
Abstract: The inclusion of a C-2 trialkylsilyl substituent into allylic amine precursors allows the base-induced aza-[2,3]-Wittig sigmatropic rearrangement to proceed in excellent yield and diastereoselectivity. The rearrangement precursors require a carbonyl-based nitrogen protecting group that must be stable to the excess of strong base required for the reaction. The N-Boc and N-benzoyl group are very good at stabilizing the product anion and initiating deprotonation. The migrating groups (G) need to stabilize the intial anion by resonance and require G-CH3 pKa > 22 in order for the initial anion to be reactive enough for rearrangement. Products 7, 20b−d,f,g, and 23 are formed with high (10−20:1) anti diastereoselectivity. Product 23 containing the morpholine amide group is useful for preparing other carbonyl derivatives.
TL;DR: The reactions of 4-(2-chloroethyl)morpholine hydrochloride with ArTe− and Te2−, generated in situ (under N2 atmosphere) have resulted in N-2-(4-methoxyphenyltelluro)ethylmorpholine (L1) and bis{2-(N-morpholino)ethyltelluride (L2), respectively, which are first tellurated derivatives of morpholine.
TL;DR: azido substituent in 1 and 2 increases the affinity 7-79-fold for rat brain and recombinant alpha4beta2 nAChRs while maintaining high potency on both insect nA ChRs (Drosophila and Myzus) (K(i)s 1-15 nM competing with [(3)H]imidacloprid).
Abstract: The 5-azido analogue of the major insecticide imidacloprid, 1-(5-azido-6-chloropyridin-3-ylmethyl)-2-nitroiminoimidaz olidine (1), and an acyclic analogue, N-(5-azido-6-chloropyridin-3-ylmethyl)-N'-methyl-N' '-nitroguanidine (2), were prepared in good yields as candidate photoaffinity probes for mammalian and insect nicotinic acetylcholine receptors (nAChRs) The essential intermediate was 5-azido-6-chloropyridin-3-ylmethyl chloride (3) prepared in two ways: from 6-chloro-5-nitronicotinic acid by selective reduction and then diazotization, and from N-(6-chloropyridin-3-ylmethyl)morpholine by an electrophilic azide introduction with lithium diisopropylamide followed by chlorine substitution of morpholine with ethyl chloroformate Coupling of 3 with 2-nitroiminoimidazolidine gave 1 Conversion of 3 to 2 was achieved in good yields via the hexahydrotriazine intermediate 14 Fortuitously, the azido substituent in 1 and 2 increases the affinity 7-79-fold for rat brain and recombinant alpha4beta2 nAChRs (K(i)s 44-60 nM competing with [(3)H](-)-nicotine) while maintaining high potency on both insect nAChRs (Drosophila and Myzus) (K(i)s 1-15 nM competing with [(3)H]imidacloprid) Azidopyridinyl compounds 1 and 2 are therefore candidate photoaffinity probes for characterization of both mammalian and insect receptors
TL;DR: The synthesis and stereochemical structure-activity relationships of novel morpholine analogues 12 and 13 with regards to NK1, NK2 and NK3 tachykinin receptor binding affinity and an essential requirement for more potent binding affinities was controlled by absolute configuration.
TL;DR: Carbon monoxide difference spectra indicated that a cytochrome-P450-dependent monooxygenase is involved in the degradation of the three cyclic amines.
Abstract: Using morpholine as sole source of carbon, nitrogen and energy, strain HE5 (DSM 44238) was isolated from forest soil. The isolated strain was identified as a member of the subgroup of fast-growing Mycobacterium species as revealed by 16S rDNA analysis. An identity of 99.4% was obtained to Mycobacterium gilvum; however, the type strain was unable to utilize morpholine. A maximal growth rate of 0.17 h(-1) was observed at a morpholine concentration of 30 mM, 30 degrees C and pH 7.2. The substrate was tolerated at concentrations up to 100 mM. Besides morpholine, the strain utilized pyrrolidine, piperidine and proposed intermediates in morpholine metabolism such as glycolate, glyoxylate and ethanolamine. Degradation of morpholine, piperidine and pyrrolidine by resting or permeabilized cells was strictly dependent on the presence of oxygen. Addition of the cytochrome-P450-specific inhibitor metyrapone to the growth medium resulted in a significantly decreased growth rate if these cyclic amines were used as a substrate. Carbon monoxide difference spectra of crude extracts from cells grown on these substrates compared to spectra obtained for extracts of succinate-grown cells indicated that cytochrome P450 is specifically expressed during growth on the cyclic amines. These data indicated that a cytochrome-P450-dependent monooxygenase is involved in the degradation of the three cyclic amines.
TL;DR: In this article, the authors showed that 1,1,2-trifluoro-2,2,hexafluoro 2,2.5,7,8-tetrahydrofuran can be converted to an N,N-dialkylamide of α-substituted fluoroacetic acid.
TL;DR: The use of disulfonylamines as counter-ions allows the synthesis of stable ionic gold(I) complexes with the amine ligands cyclohexylamine, benzylamine and 3-iodobenzenylamine as mentioned in this paper.
Abstract: The use of disulfonylamines as counter-ions allows the synthesis of stable ionic gold(I) complexes with the amine ligands cyclohexylamine, benzylamine, 3-iodobenzylamine, morpholine, pyrrolidine, and piperidine There is a considerable increase in stability for the morpholine complex compared to the previously synthesised chloro derivative; the benzylamine derivatives displayed better solubility and crystallinity than their chloro analogues The use of silver disulfonylamine derivatives in the syntheses led in two cases to the incorporation of silver into the products, with concomitantly poor yields Crystal structure determinations of eight complexes revealed, as expected, extensive systems of N−H···O hydrogen bonds Amines with NH functions tend to form hydrogen-bonded chain motifs, those with NH2 as donor group form layers of linked ring patterns It thus seems that the packing can more easily be classified in terms of influence of the cation than of the anion Some C−H···O hydrogen bonds were also observed, but play a less important role Aurophilic contacts were not observed, although one mixed gold/silver complex displayed short Au···Ag contacts Of the two compounds containing iodine, only one showed short I···I contacts
TL;DR: It is shown that carbon dioxide (CO(2)) is responsible for this kind of protective effect of morpholine carbamate formation because of formation of amine carbamates, whereas an inhibitory function of HCO(3)(-) is excluded.
Abstract: Hydrogen carbonate (bicarbonate, HCO3-) has been proposed to accelerate the decomposition of N2O3 because N-nitrosation of morpholine via a nitric oxide/oxygen mixture (•NO/O2) was inhibited by the addition of HCO3- at pH 8.9 [Caulfield, J. L., Singh, S. P., Wishnok, J. S., Deen, W. M., and Tannenbaum, S. R. (1996) J. Biol. Chem. 271, 25859−25863]. In the study presented here, it is shown that carbon dioxide (CO2) is responsible for this kind of protective effect because of formation of amine carbamates, whereas an inhibitory function of HCO3- is excluded. N-Nitrosation of morpholine (1−10 mM) at pH 7.4−7.5 by the •NO-donor compounds PAPA NONOate and MAMA NONOate (0.5 mM each) was not affected by the presence of large amounts of HCO3- (up to 100 mM) in aerated aqueous solution. Similar results were obtained by replacing the •NO-donor compounds with authentic •NO (900 μM). In agreement with data from the study cited above, •NO/O2-mediated formation of N-nitrosomorpholine (NO-Mor) was indeed inhibited by ab...
TL;DR: Tribenzyl tin(IV) chloride complexes of morpholine N-thiohydrazide (L1), aniline-N-thIOhydrazides (L2), N-(morpholine-Nthio)-1,3-propanediamine (L3) and (aniline Nthio) 1, 3-propositionediamines (L4) of the type (C6H5CH2)3Sn(L)Cl) have been synthesized in dioxane and in H2O and acetone
Abstract: Tribenzyl tin(IV) chloride complexes of morpholine N-thiohydrazide (L1), aniline-N-thiohydrazide (L2),N-(morpholine-N-thio)-1,3-propanediamine (L3) and (aniline-N-thio)-1,3-propanediamine (L4) of the type (C6H5CH2)3Sn(L)Cl (where L=L1, L2, L3 and L4) have been synthesised in dioxane and in H2O and acetone mixture. These were characterized by C,H,N-analysis, UV, IR and 1HNMR spectral studies. In both the complexes ligands act as bidentate, coordinating through sulphur and terminal nitrogen. The complexes are 1:1 metal ligand complexes. Various thermodynamic parameters have been calculated for the decomposition steps using TG/DTA curves in air as well as nitrogen atmosphere.
TL;DR: S-mono to S,S-tetrasubstituted 1,3-nitrodiene compounds 3,6 have been obtained from the reaction of 2-nitropentahalobutadiene with p-methylthiophenol as mentioned in this paper.
Abstract: S-mono to S,S-tetrasubstituted 1,3-nitrodiene compounds 3–6 have been obtained from the reaction of 2-nitropentahalobutadiene with p-methylthiophenol. Mono(thio)substituted diene compound 3 gives d...
TL;DR: An improved procedure for the radical addition of a,o-diiodoperfluoroalkanes I•(CF2CF2)n•I (na 2, 3) to allyl acetate that afford the corresponding bis-adducts AcOCH2CHICH2(CF 2CF2nCH2 CHI•CH2OAc (2a•2b) has been developed as discussed by the authors.
TL;DR: In this article, the same conditions were used to obtain stable 5-cyclopentenyl-4 H -1,3-dioxine hydrobromides (3a, 3b, 3c, 3c, 3d ).
Abstract: 5-[(2-Furyl)methylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione ( 1a ) treated with equimolar amount of pyrrolidine or hexahydroazepine afforded 5-(pyrrolidine)- ( 2a ) or 5-[(hexahydro- azepine-1-yl)-2-hydroxypenta-2,4-dien-1-ylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione ( 2d ). Their treatment with hydrobromic acid led to cyclization and formation of stable 5-cyclopentenyl-4 H -1,3-dioxine hydrobromides ( 3a , 3d ). Under the same conditions 1a treated with morpholine or piperidine yielded a mixture of 2b , 3b and 2c , 3c , respectively. The corresponding 3-substituted furans 1b - 1e gave only substituted 5-cyclopentenyl-4 H -1,3-dioxines ( 3e - 3i ). The use of an excess amine in reaction with 1a yielded unexpectedly 5-(3,5-dihetaryl-cyclopent-2-en-1-ylidene)-2,2-dimethyl-1,3-dioxane-4,6-diones ( 9a-9c ) and 5-[5-hexahydroazepin-1-ium-1-ylidene-2-(hexahydroazepin-1-yl)cyclopent-1-en-1-yl]-2,2-dimethyl-4-oxo-4 H -1,3-dioxin-6-olates ( 10 ).
TL;DR: In this article, it was shown how to transform the azavinylogous formamidinium salt with piperidine or morpholine in the presence of trime-thylborate to give the ortho formic acid amide.
Abstract: The formamidinium salts 11a, c as well as the nitrile 12 react with sodiumhydride/dimethylamine in the presence of trimethylborate to give the ortho formic acid amide 3a. The orthoamides 6a and 16 can be prepared from the iminium salts 15 and 14, resp. by the same procedure. Treatment of the azavinylogous formamidinium salt 15 with sodiumhydride and piperidine or morpholine in the presence of trime-thylborate affords the orthoamides 6c and 6d, resp. By transamination of the azavinylogous aminalester 5a are accessible the orthoamides 6b—d. The vinylogous orthocarbonic acid derivative 17 can be obtained from the salt 14 and sodium alcoholates. The action of sodiumhydride, dimethylamine and trimethylborate on the iminium salt 18 produces a mixture of the orthocarbonic acid derivatives 7a, 8a, 9a. When the guanidinium salt 20 is treated with the same reagents the ortho-amides 3a and 10a are obtained. The reduction of the salt 20 with sodiumhydride in the presence of several activating reagents (e.g. tetrabutyl orthotitanate, aluminiumisopropylate, trimethylborate) affords the orthoamide 3a. The reduction of the iminium salts 18 and 24 does not proceed clean, giving mixtures of various orthoformic acid derivatives. The form-amidine 25 can be prepared by reduction of the salt 15 with sodiumhydride/trimethylborate with good yields. By the action of the corresponding carbanions on the guanidinium salt 20 can be obtained the carboxylic acid orthoamides 26—33. By the same procedure the orthoamides of alkyne carboxylic acids 36a—h, j—n are accessible.
TL;DR: In this article, the presence of formaldehyde in solutions of cellulose in N-methylmorpholine-Noxide (NMMO, 1) has been shown by trapping formaldehyde as dimedone adduct 8 in a two-phase system, o-Dichlorobenzene was used as an inert solvent to extract the trapping product as soon as it had formed.
Abstract: The presence of formaldehyde (4) in solutions of cellulose in N-methylmorpholine-N-oxide (NMMO, 1) has been shown by trapping formaldehyde as dimedone adduct 8 in a two-phase system, o-Dichlorobenzene was used as an inert solvent to extract the trapping product as soon as it had formed. Morpholine is a degradation product of NMMO and is always present in systems containing NMMO. Formaldehyde can react with morpholine to form an intermediate carbenium-iminium ion. N-(methylene)morpholinium (6). The occurrence of 6 in the system cellulose/NMMO was demonstrated by trapping this intermediate in a Mannich type reaction with 2-acetonaphthone (9). Both formaldehyde and N-(methylene)morpholinium cations are highly reactive species readily undergoing further reactions with nucleophiles. These processes might contribute to the observed discoloration of the reaction mixture, and might also be responsible for the decomposition of NMMO that is inducible by carbenium-iminium ions.