- A convenient approach for vinylation reaction in the synthesis of 5-vinyl-2-pyrrolidinone, a key intermediate of vigabatrin
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A convenient, safe and cost-effective method for carrying out the key vinylation of 5-ethoxy-2-pyrrolidinone (8) in the preparation of 5-vinyl-2-pyrrolidinone (2) in the presence of potassium carbonate is described. This present procedure is developed by replacing inherently hazardous ethyl magnesium bromide with inexpensive and eco-friendly potassium carbonate. The reaction was performed on a multi-gram scale, with vinyl magnesium bromide as the vinylation reagent, in an 81% yield to give the 5-vinyl-2-pyrrolidinone with excellent purity and without the need for chromatography.
- Karumanchi, Kishore,Natarajan, Senthil Kumar,Gadde, Sunil,Vanchanagiri, Krishna
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- Preparation method of aminohexenoic acid
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The invention discloses a preparation method of aminohexenoic acid, which is characterized by comprising the following steps: with diethyl malonate and 1,4-dichloro-2-butene as raw materials, preparing 2-vinylcyclopropane-1,1-dicarboxylic acid diethyl ester; then carrying out a reaction on 2-vinylcyclopropane-1,1-dicarboxylic acid diethyl ester in the presence of ammonia and formamide to prepare 2-carbonyl-5-vinyl-pyrrolidine-3-amide; preparing a 4-amino-5-hexenoic acid crude product from the 2-carbonyl-5-vinyl-pyrrolidine-3-amide under an acidic condition; then preparing triisopropylsilyl-4-aminohexyl-5-alkenyl ester from 4-amino-5-hexenoic acid and triisopropylchlorosilane in the presence of triethylamine and ammonia; recrystallizing the triisopropylsilyl-4-aminohexyl-5-alkenyl ester inchloroform/methanol to obtain a purified product of the triisopropylsilyl-4-aminohexyl-5-alkenyl ester; wherein the volume ratio of chloroform to methanol is 1:7; and hydrolyzing the purified productof the triisopropylsilyl-4-aminohexyl-5-alkenyl ester under an alkaline condition to obtain the aminohexylenic acid.
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Paragraph 0016; 0040; 0050; 0051; 0057; 0058; 0061-0064
(2020/02/14)
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- A PROCESS FOR THE PREPARATION OF VIGABATRIN
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The present invention provides a process for the preparation of vigabatrin of formula (I) comprising of dissolving vigabatrin in water, optionally treating with charcoal, filtering and adding an acid to the reaction mass followed by the addition of an organic solvent and then isolating vigabatrin of formula (I) with high purity.
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Page/Page column 5; 6
(2019/10/15)
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- Process for preparing 4-amino-5-hexenoic acid from succinimide
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The present invention relates to a competitive process for the preparation of 4-amino-5-hexenoic acid and intermediates thereof. This compound is a well-known anti-epileptic drug for which several syntheses have been developed, all of them presenting drawbacks. The preparation process according to the present invention is very competitive from an economical point of view and is adapted to industrial scale preparation of 4-amino-5-hexenoic acid.
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Page/Page column 9
(2013/02/28)
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- Novel synthesis of [1-11C]γ-vinyl-γ-aminobutyric acid ([1-11C]GVG) for pharmacokinetic studies of addiction treatment
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γ-Vinyl-γ-aminobutyric acid (GVG, Vigabatrin), a suicide inhibitor of GABA-transaminase (GABA-T), has been suggested as a new drug for the treatment of substance abuse. In order to better understand its pharmacokinetics and potential side effects, we have developed a radiosynthesis of carbon-11 (t1/2=20min) labeled GVG for positron emission tomographic (PET) studies. We report here a novel synthetic strategy to prepare the precursor and to efficiently label GVG with C-11. 5-Bromo-3-(carbobenzyloxy)amino-1-pentene was synthesized in five steps from homoserine lactone, including reduction and methylenation. This was used in a one-pot, two-step radiosynthesis. Displacement of bromide with no-carrier-added [11C]cyanide followed by acid hydrolysis afforded [1-11C]GVG with decay corrected radiochemical yields of 27 ± 9% (n=6, not optimized) with respect to [11C]cyanide in a synthesis time of 45 min. Copyright
- Zhang, Zongren,Ding, Yu-Shin,Studenov, Andrei R.,Gerasimov, Madina R.,Ferrieri, Richard A.
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p. 199 - 211
(2007/10/03)
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- Process for preparing 4-amino-5-hexenoic acid
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This invention relates to a novel synthesis of 4-amino-5-hexenoic acid by thermal rearrangements, and to the novel intermediates produced thereby.
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- Vigabatrin Synthesis By Thermal Rearrangements
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Succesive thermal reactions based on a Claisen and an Overman rearrangements furnish an original access to vigabatrin starting from erythritol.
- Casara, Patrick
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p. 3049 - 3050
(2007/10/02)
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- Process for making 4-aminohex-5-enoic acid
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Novel compounds of the following general formula are useful in the preparation of 4-aminohex-5-enoic acid and 4-aminohex-5-ynoic acid which are useful pharmacological agents: STR1 wherein R1 is hydroxy, amino, or tert-butoxy.
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