- PURIFICATION OF 1,3-PROPANEDIOL BY DISTILLATION
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The present invention is a process for purification of 1,3-propanediol (PDO) by an inverted distillation sequence which comprises: (a) optionally removing water or other solvents from the crude 1,3-propanediol mixture; (b) distilling the crude 1,3-propanediol mixture under conditions which maximize the separation of components of the mixture which are heavier than 1,3-propanediol from the 1,3-propanediol and the components which are lighter than 1,3-propanediol; (c) drawing off a stream which contains at least most of the 1,3-propanediol and at least some of the components of the mixture which are lighter than 1,3-propanediol; and (d) distilling the stream of (c) to separate the 1,3-propanediol from components in the stream which are lighter than 1,3-propanediol and any residual components which are heavier than 1,3-propanediol.
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- Amidrazones. 14. The Formation of 1,1-Disubstituted Hydrazines from the Base-promoted Hydrolysis of 1,1-Disubstituted-3-amino-4,5-dihydro-1H-pyrazolium Halides: Mechanistic Considerations
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Three mechanistic pathways are considered for the hydroxide-promoted conversion of 1,1-disubstituted-3-amino-4,5-dihydro-1H-pyrazolium halides 1 to 1,1-disubstituted hydrazines, ammonia and sodium 3-hydroxypropanoate.Evidence presented in this paper supports a hydrolysis mechanism c that is initiated by hydroxide ion addition to the 3-position of 1 to form a tetrahedral intermediate 7.
- Smith, Richard F.,Dennis, Lisa A.,Ryan, William J.,Rodriguez, George,Brophy, Keith A.
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p. 181 - 183
(2007/10/02)
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- AMIDRAZONES 9. CONVENIENT SYNTHESIS OF 1-ALKYL-1-PHENYLHYDRAZINES AND α,β-UNSATURATED AMIDRAZONES VIA BASE-PROMOTED REACTIONS OF 1,1-DISUBSTITUTED-3-AMNIO-4,5-DIHYDRO-1H-PYRAZOLIUM SALTS.
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A simple, efficient procedure for the conversion of phenylhydrazine to 1-alkyl-1-phenylhydrazines via base-promoted hydrolysis of 1-alkyl-3-amino-4,5-dihydro-1-phenyl-1H-pyrazolium iodides (2) is described.N',N'-disubstituted hydrazones of trans-cinnamamide and acrylamide are obtained by Hofmann-type ring openings of 1,1-disubstituted-3-amino-4,5-dihydro-5-phenyl (or 5-unsubstituted) -1H-pyrazolium halides (5,7).
- Smith, Richard F.,Olson, Laurie A.,Ryan, William J.,Coffman, Karen J.,Galante, Julienne M.,et al.
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p. 585 - 596
(2007/10/02)
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