29144-31-8Relevant articles and documents
On the formation of a side product with hexahydroaporphine-like structure in the Grewe cyclization of dextromethorphan
Zhao, Qiao,Zhao, Kai,Wu, Sheng-ying,Tian, Bo-xue,Eriksson, Leif A.,Wang, Li-min,An, Na,Long, Zhong-zhu,Cai, Shui-hong
, p. 1689 - 1708 (2017/02/15)
Factors leading to the formation of a hexahydroaporphine-like cyclizing side product were studied systematically for the first time and the ratio of this side product was controlled effectively. To understand better the electronic effect of substrates on the formation of side products, different 1-benzyloctahydroisoquinolines with substituted groups on nitrogen or benzene ring were compared. A plausible mechanism of cyclizing reaction was proposed, and key intermediates as well as transition states were analyzed using DFT calculations.
An improved process for the preparation of (+)-3- Methoxy-N-formylmorphinan
Kumaraguru, Thenkrishnan,Fadnavis, Nitin W.
, p. 174 - 178 (2014/05/20)
Two major steps, N-formylation of (-)-octabase and cyclization of the N-formylated product, involved in synthesis of (+)-3-methoxy-N-formylmorphinan, a key intermediate for production of dextromethorphan (DXM), have been improved to achieve higher yields in shorter time with fewer effluents. Methods of analysis of chemical and enantiomeric purities of the intermediates by HPLC and strategies for easy recovery and recycle of the reagents have been devised.
COMPOSITIONS AND METHODS FOR THE TREATMENT OF RESPIRATORY DISORDERS
-
, (2013/12/03)
The invention relates to the compounds of formula (I) or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof. The pharmaceutical compositions comprising an effective amount of compounds of formula (I), and methods for the treatment of respiratory disorders may be formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenteral administration, syrup, or injection. Such compositions may be used to treatment of cough caused by minor throat and bronchial irritation (such as commonly accompanies the flu and common cold), as well as those resulting from inhaled particle irritants, upper respiratory infections, (pseudobulbar affect) in patients with amyotrophic lateral sclerosis and multiple sclerosis, neuropathic pain and pain associated with fibromyalgia.
General asymmetric synthesis of isoquinoline alkaloids. Enantioselective hydrogenation of enamides catalyzed by BINAP-ruthenium(II) complexes
Kitamura,Hsiao,Ohta,Tsukamoto,Ohta,Takaya,Noyori
, p. 297 - 310 (2007/10/02)
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.
New efficient methods for the synthesis and in-situ preparation of ruthenium(II) complexes of atropisomeric diphosphines and their application in asymmetric catalytic hydrogenations
Heiser,Broger,Crameri
, p. 51 - 62 (2007/12/18)
A new synthetically useful method for the synthesis of the diphosphine ruthenium dicarboxylato complexes (P-P)Ru(O2CR)2(R= CF3 and CH3) is presented, which uses the easily accessible complex (COD)2Ru2(μ-O2CCF3)4 as starting material. This complex as well as (COD)(Ru(ηO2CCH3)2 and (COD)2Ru2Cl4(NCCH3) have been shown to be suitable precursor complexes for the in-situ preparation of ruthenium(II) dicarboxylato and dichloro complexes of atropisomeric diphosphines, respectively. The high efficacy of the preformed and in-situ generated ruthenium complexes as precatalysts is demonstrated in asymmetric hydrogenations of allylic alcohols, enamides, and a β-keto ester.
GENERAL ASYMMETRIC SYNTHESIS OF BENZOMORPHANS AND MORPHINANS VIA ENANTIOSELECTIVE HYDROGENATION
Kitamura, M.,Hsiao, Yi,Noyori, R.,Takaya, H.
, p. 4829 - 4832 (2007/10/02)
A variety of optically active benzomorphans including metazocine and pentazocine as well as dextromethorphan, a morphinan, are obtainable by using the BINAP-ruthenium(II) catalyzed enantioselective hydrogenation as key operation.
