50896-90-7

The invention discloses a method for synthesizing cisatracurium besilate. The method comprises the following steps of: reacting a compound shown as formula I, a compound shown as formula II and oxalicacid dihydrate to generate a compound shown as formula III; reacting the compound shown as formula III under the catalysis of Pd/C to generate a compound shown as formula IV; reacting the compound shown as formula IV with 1, 5-pentanediol to generate a compound shown as formula V; and reacting the compound shown as formula V with methyl benzenesulfonate to prepare cisatracurium besilate; whereinthe compounds shown as the formula I, the formula II, the formula III, the formula IV and the formula V are respectively represented as the specification. The synthesis method provided by the invention can significantly improve the yield and purity of cisatracurium besilate and reduce the synthesis cost of cisatracurium besilate.

The invention relates to a preparation method of a benzyl tetrahydro isoquinoline compound. The preparation method is characterized by including: adding specific chiral organic acid into a mixture containing a compound as shown in formula (I) to form salt. The preparation method has the advantages that high product yield is guaranteed while the chemical purity and optical purity of the product areincreased greatly, the total yield increasing and product quality control in the synthesizing process of a mivacurium chloride or cisatracurium besilate finished product are benefited, a powerful guarantee is provided for the safety and effectiveness of finished-product medicine, and the method is suitable for industrial production.

α-Amino nitrile 2a was conveniently prepared in two individual steps from chiral hexafluorophosphate salt isoquinolinium (-)-8b including anodic cyanation as an efficient means to activate the sp3 C1-H bond of the THIQ nucleus. The lithiation o

A process for the resolution of racemic tetrahydropapaverine with optically active arylpropionic acids is described.

A process for the resolution of racemic tetrahydropapaverine with optically active arylpropionic acids is described.

A short asymmetric synthesis of 1-substituted 1,2,3,4- tetrahydroisoquinoline alkaloids by deprotonation of an unprotected α-aminonitrile and alkylation of the resulting carbanion followed by spontaneous elimination of HCN and asymmetric reduction is described. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.

The study presents a new pathway for the enantioselective synthesis of benzylisoquinoline alkaloids. The key steps of the synthesis of (+)-(S)-laudanosine (1) and (-)-(S)-xylopinine (2) are a Sonogashira coupling that builds up the C1-C8a bond of the benzylisoquinoline skeleton, an intramolecular Ti-catalyzed hydroamination of an alkyne, and a subsequent enantioselective imine reduction according to Noyori's protocol.

A novel, direct, and high-yielding stereoselective method for enantiopure 1-substituted tetrahydroisoquinolines (THIQ) is described. The successful approach, which creates the stereocenter during the formation of the THIQ nucleus is based on (i) formation of chiral 2,3-substituted perhydro-1,3-benzoxazines derived from (-)-8-aminomenthol, (ii) diastereoselective intramolecular ring opening of the N,O-acetal moiety by an arylmetal generated from the substituent at the nitrogen atom in the perhydrobenzoxazine ring, and (iii) removal of the chiral auxiliary appendage. The starting perhydrobenzoxazines are easily prepared from (-)-8-aminomenthol and two different aldehydes, and the intramolecular opening is stereospecific, leading to a single stereoisomer. The method allows the preparation of a wide variety of enantiopure 1-substituted THIQ, with different substituents at C-1, by changing the nature of the starting aldehydes.

The addition of the lithium carbanion of (R)-(+)-3,4-dimethoxybenzyl 2-methoxy-1-naphthyl sulfoxide 3 to cyclic nitrone 4, under kinetically controlled conditions gave isoquinoline sulfoxide derivatives 5 and 6 in high diastereoselectivities. Under equilibrium controlled conditions poor diastereoselectivity results. The chiral (R)-(+)-3,4-dimethoxybenzyl 2-methoxy-1-naphthyl sulfoxide 3 was easily prepared by the reaction of 3,4-dimethoxybenzylmagnesium chloride 2 with (-)-(S) menthyl 2-methoxy-naphthalene sulfinate 1 in dry benzene. This methodology allows for the synthesis of the isoquinoline alkaloid (R)-(-)-norlaudanosine 8 in three efficient synthetic steps.

Thiazazincolidine complexes, 2, were shown to be excellent catalysts for enantioselective reduction of dihydroisoquinolines 1 with BH3 · THF to the corresponding amines in good ee.

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Optically active 1,2,3,4-tetrahydroisoquinoline alkaloids, (S)-norlaudanosine and (S)-tetrahydrohomopapaverine, were prepared by catalytic asymmetric hydrogenation of 1-substituted 3,4-dihydro-6,7-dimethoxyisoquinolines with 1 mol % of an iridium(I) compl

L-Ascorbic acid 1 was converted into L-gulonolactone 2 by catalytic hydrogenation. Treatment of 2 with 3,4-dimethoxyphenylethyl amine 3 afforded amide 4, which in several steps was transformed into the title alkaloids in good enantiomeric excesses. Also, chromium(III) oxide is proposed as an effective catalyst for the conversion of (R)-(-)-laudanosine into (R)-(-)-glaucine.

In the presence of a small amount of RuX2[(R)- or (S)-BINAP] (X = anionic ligand) a wide range of (Z)-2-acyl-1-benzylidene-1,2,3,4- tetrahydroisoquinolines are hydrogenated to give the saturated products in nearly quantitative yields and in high (up to 100%) optical yields. The enamide substrates are selectively prepared by N-acylation of the corresponding 1-benzylated 3,4-dihydroisoquinolines under suitable acylation conditions; some crystalline materials having low solubility are obtained by a second-order Z/E stereomutation technique utilizing the double-bond photolability and lattice energy effects. This asymmetric hydrogenation sets the key stereogenic center in a predictable manner, either R or S flexibly, at the C(1) position of the benzylated tetrahydroisoquinolines. The chiral products are converted by standard functional group modification to tetrahydropapaverine, laudanosine, tretoquinol, norreticuline, etc. Hydrogenation of the simple 1-methylene substrate is used for synthesis of salsolidine. This enantioselective hydrogenation is applied to the synthesis of morphine and its artificial analogues such as morphinans and benzomorphans of either chirality. A mnemonic device is presented for predicting the reactivity and enantiofacial selection of the BINAP-Ru catalyzed hydrogenation. Reaction with BINAP-Rh catalyst proceeds with a lower enantioselectivity and an opposite sense of asymmetric induction.

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