Morpholine

About: Morpholine is a(n) research topic. Over the lifetime, 5411 publication(s) have been published within this topic receiving 51063 citation(s). The topic is also known as: diethylene imidoxide & diethylene oximide.

Ascorbate-Nitrite Reaction: Possible Means of Blocking the Formation of Carcinogenic N-Nitroso Compounds

Abstract: The formation of carcinogenic N-nitroso compounds by the chemical reaction between nitrous acid and oxytetracycline, morpholine, piperazine, N-methylaniline, methylurea, and (in some experiments) dimethylamine was blocked by ascorbic acid. The extent of blocking depended on the compound nitrosated and on the experimental conditions. Urea and ammonium sulfamate were less effective as blocking agents. The possibility of in vivo formation of carcinogenic N-nitroso compounds from drugs could be lessened by the combination of such drugs with the ascorbic acid.

Kinetics and mechanism of the reaction between carbon dioxide and amines in aqueous solution

Abstract: Rate constants, ΔH‡ and ΔS‡ have been measured by the conductimetric stopped-flow technique for the reaction of carbon dioxide in aqueous solution with the primary amines 2-methoxyethylamine, 2-aminoethanol, 3-aminopropan-1-ol, 2-aminopropan-2-ol, DL-aminopropan-2-ol and the secondary amines 1,1′-iminodipropan-2-ol, 2-amino-2-(hydroxymethyl) propane-1,3-diol, 2,2′-iminodiethanol, 2,2,6,6-tetramethylpiperidin-4-ol, and morpholine. The observed first-order rate constants fit the equation kobs=kAM[R2NH]2+kW[R2NH][H2O]. The much-quoted Danckwerts mechanism is shown to be unlikely.

β-Cyanoethyl N,N-dialkylamino/N-morpholinomonochloro phosphoamidites, new phosphitylating agents facilitating ease of deprotection and work-up of synthesized oligonucleotides

Abstract: β-Cyanoethyl monochlorophosphoamidites of the secondary amines N,N-dmethylamine, N,N-diisopropylamine and morpholine have been prepared which showed quantitative phosphitylation of the protected deoxynucleosides. The phosphitylated deoxynucleosides have successfully been used in the formation of internucleotidic bonds. β-Cyanoethyl nucleoside-3′-N,N-diisopropylphosphoamidites have satisfactorily been used for the synthesis of the oligodeoxynucleotide d(CGGTACCG).

High turnover number and rapid, room-temperature amination of chloroarenes using saturated carbene ligands.

Abstract: A catalytic system for the mild amination of aryl chlorides is described. This system consists of a Pd(0) precursor and a dihydroimidazoline carbene ligand, which is generated in situ from its protonated tetrafluoroborate salt (2). Using this catalyst, aryl and heteroaryl chlorides react with secondary amines and anilines within hours at room temperature. Turnover numbers as high as 5000 are obtained at elevated temperatures for reaction of morpholine with an unactivated aryl chloride.

Noncomplexing Tertiary Amines as “Better” Buffers Covering the Range of pH 3−11. Temperature Dependence of Their Acid Dissociation Constants

Abstract: Most of a broad series of buffers developed by Good (often called “Good's” or “Good” buffers) have been shown to cause metal ion interference as a result of complexation. A series of tertiary amines, devoid of hydroxy groups or other weak donors on the α, β, or γ carbons, have been developed as “Better” pH buffers which, as a result of steric hindrance, are incapable of forming even weak complexes with metal ions. As a result, they avert interferences of the type often encountered in metal ion studies which require buffer use. The compounds studied are alkyl and alkylsulfonate derivatives of morpholine (3), piperazine (3), ethylenediamine (3), and methylenediamine (1). With the exception of the morpholine derivatives, these compounds have two protonatable sites and, therefore, can be used to buffer two separate pH regions. A series of 10 buffer compounds span the entire range of pH 3−11. The acid dissociation constants for these compounds have now been determined in aqueous solution at 15, 25, 35 and 45 °...