Morpholine

About: Morpholine is a research topic. Over the lifetime, 5411 publications have been published within this topic receiving 51063 citations. The topic is also known as: diethylene imidoxide & diethylene oximide.

Synthesis and Structure of 2-Ethoxy- and 2-Aminomethylidene- 3-fluoroalkyl-3-oxopropionates

Abstract: Condensation of ethyl 3-polyfluoroalkyl-3-oxopropionates with excess triethyl orthoformate gave ethyl 3-polyfluoroalkyl-2-ethoxymethylidene-3-oxopropionates which reacted with primary aliphatic, aromatic, and heterocyclic amines to form ethyl 2-alkyl(aryl, hetaryl)aminomethylidene-3-polyfluoroalkyl-3-oxopropionates. According to the X-ray diffraction and IR data, the latter exist in the crystalline state as the corresponding E isomers, while in solution (NMR data), as mixtures of Z and E isomers. Condensation of ethyl 2-ethoxymethylidene-3-oxopropionates with secondary heterocyclic amines (morpholine and pyrrolidine) led to the formation of 2-morpholino(pyrrolidin-1-yl)methylidene-3-fluoroalkyl-3-oxopropionates which were shown to exist as Z isomers both in the crystalline state and in solution.

Degradation of morpholine and thiomorpholine by an environmental Mycobacterium involves a cytochrome P450. Direct evidence of intermediates by in situ NMR

Abstract: A strain of Mycobacterium sp. RP1 was isolated from a contaminated activated sludge. It was capable of utilizing morpholine, a waste of chemical industry, as sole source of carbon, nitrogen and energy. The kinetic of biodegradation of morpholine was followed directly on the incubation medium using in situ 1 H NMR. This technic allowed to identify two intermediates of the degradative pathway: glycolate and 2-(2-aminoethoxy)acetate. The inhibitory effects of metyrapone on the degradative abilities of the strain RP1 indicated the involvement of a cytochrome P 450. This observation was confirmed by spectrophotometric analysis and 1 H NMR. Metyrapol, a known metabolite of metyrapone, was also found to be an inhibitor. The same study of degradation of thiomorpholine showed the formation of sulfoxide, which confirmed the presence of a cytochrome P 450.

Stereoselective Polymer-Supported Synthesis of Morpholine- and Thiomorpholine-3-carboxylic Acid Derivatives.

Abstract: Herein we report the polymer-supported synthesis of 3,4-dihydro-2H-1,4-oxazine-3-carboxylic acid derivatives using immobilized Fmoc-Ser(tBu)-OH and Fmoc-Thr(tBu)-OH as the starting materials. After the solid-phase-synthesis of N-alkyl-N-sulfonyl/acyl intermediates, the target dihydrooxazines were obtained using trifluoroacetic acid-mediated cleavage from the resin. This approach was also studied for the preparation of dihydrothiazines from immobilized Fmoc-Cys(Trt)-OH. Inclusion of triethylsilane in the cleavage cocktail resulted in the stereoselective formation of the corresponding morpholine/thiomorpholine-3-carboxylic acids. Stereochemical studies revealed the specific configuration of the newly formed stereocenter and also the formation of stable N-acylmorpholine rotamers.

5-Azidoimidacloprid and an Acyclic Analogue as Candidate Photoaffinity Probes for Mammalian and Insect Nicotinic Acetylcholine Receptors

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

Base strength of amines at high temperatures. Ionization of cyclohexylamine and morpholine

Abstract: A potentiometric technique using a hydrogen electrode concentration cell with flowing solutions was employed to measure the ionization equilibria of cyclohexylamine and morpholine over the temperature range 50–295°C in dilute KCl media. Also, the isothermal pressure coefficients were determined to 250°C in the same media. Smoothing functions are presented which fit these and other selected data, and thermodynamic quantities for the ionization process were derived. Nearly linear variation of ΔH vsT ΔS was observed for this process as well as other similar reactions, and the significance is discussed. Differences in basicities of amines are found to decrease at elevated temperatures, and reversals in relative base strengths are seen.