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.

The Dimerization of Butadiene by Palladium Complex Catalysts

Abstract: It has been found that palladium-phosphine complexes coordinated by dienophile and tetrakis-(triphenylphosphine) palladium catalyzed the linear dimerization of butadiene. The dimerization of butadiene with bis(triphenylphosphine)(maleic anhydride)palladium in aprotic solvents, such as benzene, tetrahydrofuran, and acetone, gave octatriene-1,3,7 selectively in good yields. In such alcohols as methanol, ethanol, and isopropanol, butadiene was converted to 1-alkoxyoctadiene-2,7 and/or octatriene-1,3,7, depending on the nature of the alcohols employed. The dimerization in secondary amines, such as morpholine, piperidine, and diisopropylamine, gave butadiene dimer-amine adducts of the R2N(C8H13) type, while that in primary amines, such as aniline and n-butylamine, gave a mixture of RNH(C8H13) and RN(C8H13)2. Phenoxy- and acetoxyoctadiene were also obtained from the reactions in phenol and acetic acid respectively.

Study of aromatic nucleophilic substitution with amines on nitrothiophenes in room-temperature ionic liquids: are the different effects on the behavior of para-like and ortho-like isomers on going from conventional solvents to room-temperature ionic liquids related to solvation effects?

Abstract: The kinetics of the nucleophilic aromatic substitution of some 2-L-5-nitrothiophenes (para-like isomers) with three different amines (pyrrolidine, piperidine, and morpholine) were studied in three room-temperature ionic liquids ([bmim][BF4], [bmim][PF6], and [bm(2)im][BF4], where bmim = 1-butyl-3-methylimidazolium and bm(2)im = 1-butyl-2,3-dimethylimidazolium). To calculate thermodynamic parameters, a useful instrument to gain information concerning reagent-solvent interactions, the reaction was carried out over the temperature range 293-313 K. The reaction occurs faster in ionic liquids than in conventional solvents (methanol, benzene), a dependence of rate constants on amine concentration similar to that observed in methanol, suggesting a parallel behavior. The above reaction also was studied with 2-bromo-3-nitrothiophene, an ortho-like derivative able to give peculiar intramolecular interactions in the transition state, which are strongly affected by the reaction medium.

Morpholine as a privileged structure: A review on the medicinal chemistry and pharmacological activity of morpholine containing bioactive molecules.

Abstract: Morpholine is a heterocycle featured in numerous approved and experimental drugs as well as bioactive molecules. It is often employed in the field of medicinal chemistry for its advantageous physicochemical, biological, and metabolic properties, as well as its facile synthetic routes. The morpholine ring is a versatile and readily accessible synthetic building block, it is easily introduced as an amine reagent or can be built according to a variety of available synthetic methodologies. This versatile scaffold, appropriately substituted, possesses a wide range of biological activities. There are many examples of molecular targets of morpholine bioactive in which the significant contribution of the morpholine moiety has been demonstrated; it is an integral component of the pharmacophore for certain enzyme active-site inhibitors whereas it bestows selective affinity for a wide range of receptors. A large body of in vivo studies has demonstrated morpholine's potential to not only increase potency but also provide compounds with desirable drug-like properties and improved pharamacokinetics. In this review we describe the medicinal chemistry/pharmacological activity of morpholine derivatives on various therapeutically related molecular targets, attempting to highlight the importance of the morpholine ring in drug design and development as well as to justify its classification as a privileged structure.