- A chemo-enzymatic route to enantiomerically pure cyclic tertiary amines
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Deracemization of racemic chiral tertiary amines has been achieved by combination of an enantioselective amine oxidase, obtained through directed evolution, and ammonia borane in a one-pot process. Copyright
- Dunsmore, Colin J.,Carr, Reuben,Fleming, Toni,Turner, Nicholas J.
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- Asymmetric preparation method of nicotine
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The invention relates to a preparation method of nicotine, in particular to a preparation method of nicotine from nicotinic acid ester as a starting material through five-step reaction. The method comprises the following specific steps: (1) a condensation reaction of the nicotinate with N - methylpyrrolidinone in a suitable reaction vessel, and adding a strong acid to react to obtain 4 - methylamino -1 - (3 - pyridine) - butanone hydrochloride after the reaction is finished. (2) The amino group is protected with a suitable amino protecting reagent to give an intermediate (4). (3) The chiral alcohol intermediate (5) is obtained by asymmetric reduction. (4) The chiral alcohol intermediate can be converted into nicotine through two-step conversion. The asymmetric reduction reaction of metal catalysis is a key step of the method, so that the chiral alcohol intermediate with high optical activity can be obtained, and nicotine can be prepared through two-step conversion. The nicotine preparation method provided by the invention is simple to operate, low in cost, mild in reaction condition and suitable for industrial production.
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Paragraph 0115-0118
(2021/10/27)
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- Synthesis of [4-2H2]-, (4R)[4-2H1]-and (4S)[4-2H1]- 4-(methylnitrosamino)-1 -(3′-pyridyl)-1-butanone, c-4 deuteriated isotopomers of the procarcinogen nnk
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The synthesis of C-4 dideuteriated and both C-4 monodeuteriated enantiomers of NNK, the metabolic precursor to a variety of potential carcinogens, starting from (2S)-glutamic acid and nicotinic acid is described. The route is suitable for the synthesis of NNK isotopomers labelled in each of the putative sites for metabolic activation.
- Pathak, Tanmaya,Thomas, Noel F.,Akhtar, Mahmoud,Gani, David
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p. 1733 - 1744
(2007/10/02)
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- Ring-Chain Tautomerism of Pseudooxynicotine and Some Other Iminium Compounds
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The ring-chain tautomerism in aqueous solution of the nicotine metabolite pseudooxynicotine (1) has been studied.Of the four possible forms of 1, only the chain form 1a and the iminium form 1c could be observed by NMR spectroscopy.The chain form 1a was strongly preponderant at high or low pH.The proportion of 1c reached a maximum level of 52-53 percent in a neutral solution of 1.These results differ strongly from those published by other workers.Some analogous compounds (e.g. 5 and 6) have also been investigated.
- Brandaenge, Svante,Lindblom, Lars,Pilotti, Ake,Rodriguez, Benito
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p. 617 - 622
(2007/10/02)
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