Three Stereoisomers of a Novel and Selective μ-Opioid Analgesic
摘要:
The crystal structures of the following three stereoisomers have been determined: (1S)-2-[(1R,1'R)-, (1S)-2-[(1S,1'S)- and (1S)-2-[(1R,1'S)-bis(l-methylpropyl)amino]-1-[(5S)-1- [(2-chlorophenyl)methyl]-2-oxo-5-pyrrolidinyl]ethanol, C21H33ClN2O2 The configurations at the stereocentres strongly influence both the hydrogen-bonding behaviour of the OH group and the packing. The conformations of the central N-C-C(OH)-C-N chains are particularly relevant to this behaviour and to the pharmacological activity.
Chiral synthesis via organoboranes. 28. Reaction of .alpha.-chiral organyldichloroboranes with organyl azides providing a synthesis of secondary amines with exceptionally high enantiomeric purities
摘要:
2-Alkyl-1,3,2-dioxaborinanes R*BO2(CH2)3 of essentially 100% enantiomeric purity were prepared by the asymmetric hydroboration of readily available prochiral olefins with mono- or diisopinocampheylboranes, followed by removal of the chiral auxiliary (alpha-pinene). The intermediate R*BO2(CH2)3 reacts readily with lithium aluminum hydride at 0-degrees-C to give the corresponding lithium monoalkylborohydrides stereospecifically in very good yields and in very high enantiomeric purities. The lithium monoalkylborohydrides, on treatment with hydrogen chloride in dimethyl sulfide, give the corresponding monoalkyldichloroboranes in very high enantiomeric purity. The intermediate monoalkyldichloroboranes react readily with organic azides in 1,2-dichloroethane with evolution of gaseous nitrogen and transfer of the organic group from boron to nitrogen with complete retention of configuration to provide the corresponding secondary amines, either (+)- or (-), in very high yields and exceptionally high enantiomeric purities. The procedure was applied to the synthesis of representative optically active amines of high enantiomeric purities (ee or de greater-than-or-equal-to 99%), including (2S,2'S)-di-2-butylamine, N-[(2S)-2-methyl-1-butyl]-(1S,2R)-trans-2-phenycyclopentylamine, N-[(3S)-3,7-dimethyloct-6-enyl](1S,2S)-trans-2-methylcyclohexylamine, and the meso-di-2-butylamine.
Heat transfer liquid composition and energy saving heating method using it
申请人:Stephano CHM gcv
公开号:EP2799511A2
公开(公告)日:2014-11-05
This invention provides a heat transfer liquid medium comprising a mixture of water and a reaction product of an alkanolamine wherein the alkyl group has from 2 to 4 carbon atoms and an inorganic acid having a pKa from 1 to 14, wherein the weight proportion of water in said mixture is from 10% to 95%, and wherein the weight proportion of the reaction product in said mixture is from 5% to 90%.
When used in a circulating system for heating a room, this heat transfer liquid medium provides significant energy and cost savings.