54417-53-7Relevant academic research and scientific papers
Half-quantity resolution method of racemic mixture of tetrahydroisoquinoline type compound
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Paragraph 0040-0043; 0046; 0058, (2017/10/13)
The invention discloses a half-quantity resolution method of a racemic mixture of a tetrahydroisoquinoline type compound. The half-quantity resolution method comprises the following steps: dissolving hydrochloride of the tetrahydroisoquinoline type compound into water and alkalifying under an alkaline condition to obtain the racemic mixture; dissolving the racemic mixture into a polar solvent; under a heating condition, enabling the racemic mixture to react with a single half-quantity resolution agent N-acyl-D-amino acid or D-diphenylacyl tartaric acid, so as to form salt; or after enabling the racemic mixture to react with the resolution agent N-acyl-D-amino acid for a period of time, adding the other resolution agent D-diphenylacyl tartaric acid and reacting to form the salt; after reacting, slowly cooling and crystalizing and carrying out a post-treatment process, so as to directly obtain R configuration tetrahydroisoquinoline type compound salt with high optical purity. According to the half-quantity resolution method, the half quantity of the mixed resolution agent or the half quantity of the single resolution agent is utilized, so that the dosage of the resolution agent is saved; recrystallization is not needed and a design is reasonable; the preparation method is simple and convenient and has high practicability; the total yield of an R configuration product can reach 83.25 percent at maximum and the purity can reach 97 percent or more at maximum.
Organocatalytic Enantioselective Pictet-Spengler Approach to Biologically Relevant 1-Benzyl-1,2,3,4-Tetrahydroisoquinoline Alkaloids
Ruiz-Olalla, Andrea,Würdemann, Martien A.,Wanner, Martin J.,Ingemann, Steen,Van Maarseveen, Jan H.,Hiemstra, Henk
, p. 5125 - 5132 (2015/05/27)
(Figure Presented) A general procedure for the synthesis of 1-benzyl-1,2,3,4-tetrahydroisoquinolines was developed, based on organocatalytic, regio- and enantioselective Pictet-Spengler reactions (86-92% ee) of N-(o-nitrophenylsulfenyl)-2-arylethylamines with arylacetaldehydes. The presence of the o-nitrophenylsulfenyl group, together with the MOM-protection in the catechol part of the tetrahydroisoquinoline ring system, appeared to be a productive combination. To demonstrate the versatility of this approach, 10 biologically and pharmaceutically relevant alkaloids were prepared using (R)-TRIP as the chiral catalyst: (R)-norcoclaurine, (R)-coclaurine, (R)-norreticuline, (R)-reticuline, (R)-trimemetoquinol, (R)-armepavine, (R)-norprotosinomenine, (R)-protosinomenine, (R)-laudanosine, and (R)-5-methoxylaudanosine.
PROCESS FOR THE RESOLUTION OF ISOQUINOLINE DERIVATIVES
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Page/Page column 5, (2010/12/29)
A process for the resolution of racemic tetrahydropapaverine with optically active arylpropionic acids is described.
PROCESS FOR THE RESOLUTION OF ISOQUINOLINE DERIVATIVES
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Page/Page column 9-10, (2009/10/21)
A process for the resolution of racemic tetrahydropapaverine with optically active arylpropionic acids is described.
Asymmetric Reduction of Cyclic Imines with Chiral Sodium Acyloxyborohydrides
Yamada, Koichiro,Takeda, Mikio,Iwakuma, Takeo
, p. 265 - 270 (2007/10/02)
Asymmetric reduction of prochiral cyclic imines with chiral sodium acyloxyborohydrides (5a-i), which are easily prepared by the reaction of NaBH4 with various N-acyl α-amino-acids, has been investigated.Of these new reducing agents, triacyloxyborohydrides (5c-f), derived from NaBH4 (1 equiv.) and (S)-N-acylproline (3 equiv.), were found to reduce 3,4-dihydropapaverine (2) in tetrahydrofuran to (S)-norlaudanosine (3) hydrochloride in 60percent optical yield.The N-benzyloxycarbonyl derivative (5c) could be isolated as a powder and characterized.The effect of solvents on this asymmetric reduction has been examined by the use of the isolated reagent (5c); halogenated alkane solvents such as CH2Cl2 or CHCl2CH3 gave a better optical yield of compound (3) (79percent e.e.).The reagent (5c) also reduced other cyclic imines (6a-c) and (8) to the corresponding alkaloids (7a-c) and (9) in excellent optical yields (70-86percent e.e.), providing an effective route to the asymmetric synthesis of these alkaloids.A possible reaction path for this reduction is also presented.
A Novel Asymmetric Reduction of Imines with Chiral Sodium Triacyloxyborohydrides
Yamada, Koichiro,Takeda, Mikio,Iwakuma, Takeo
, p. 3869 - 3872 (2007/10/02)
There has been described a novel and convenient synthesis of optically active alkaloids by the asymmetric reduction of cyclic imines using the chiral sodium triacyloxyborohydrides, easily prepared from the reaction of NaBH4 and N-acyl L-prolines.
