5220-49-5Relevant articles and documents
Total synthesis of (±)-tangutorine and chiral HPLC separation of enantiomers
Putkonen, Tiina,Tolvanen, Arto,Jokela, Reija,Caccamese, Salvatore,Parrinello, Nunziatina
, p. 8589 - 8595 (2003)
The first total synthesis of racemic tangutorine, a novel indole alkaloid, was performed in 7 steps. The key reactions, dithionite reduction and acidic cyclization provided easy access with good yields to the tangutorine skeleton. Comprehensive NMR spectroscopic data of new compounds are given. Chiral HPLC separation of enantiomers is reported.
Efficient synthesis of decahydroacridine-1,8-diones and polyhydroquinolines using the step-wise method
Hosseininasab, Fatemeh Sadat,Memarian, Hamid Reza
, (2022/01/11)
Various symmetrical and unsymmetrical decahydroacridine-1,8-dione and polyhydroquinoline derivatives were synthesized via two-step cyclocondensation reactions. The advantages of this step-wise addition of reactants in comparison with other one-pot reactions are avoiding the formation of 2 or 3 undesired by-products, therefore allowing cleaner work up of reaction. The important factor of this effective cyclocondensation method is that the prepared β-enaminone component was added dropwise to the solution, in which the Knoevenagel condensation product is slowly being formed by reaction of aldehyde molecule and 1,3-dicarbonyl compounds. The results of the proposed step-wise method are compared and discussed with those obtained in the one-pot reactions.
Cu catalyzed cross-dehydrogenative coupling reaction for the synthesis of 3-hydroxy-2-pyrrolidinones
Sarkar, Rajib,Mukhopadhyay, Chhanda
supporting information, p. 3069 - 3076 (2018/07/06)
A new convenient strategy for the synthesis of 3-hydroxy-2-pyrrolidinone derivatives featuring regioselective C–C coupling has been developed. This is a Cu (II) catalyzed cross dehydrogenative coupling (CDC) involving enamino-ketones of benzyl amines and di-alkyl acetylenedicarboxylate, followed by cyclization by primary amines. TBHP (tert-butyl hydroperoxide) has been used as the oxidant to promote the coupling protocol. This synthetic route principally demonstrates the scope of CDC reaction and also applicable to gram-scale synthesis.
Stable carteolol hydrochloride, preparation method thereof and eye medicine combination
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Paragraph 0120; 0123; 0135; 0144-0146; 0157; 0168; 0179, (2017/12/06)
The invention relates to stable carteolol hydrochloride, a preparation method thereof and an eye medicine combination, in particular to a method for preparing carteolol hydrochloride. The method comprises the following steps of preparing 3-amino-2-cyclohexenone, tetrahydro-2,5(1H, 6H)-quinolinone, 5-hydroxy-3,4-dihydro-2(1H)-carbostyril and 5-(2,3-epoxypropoxy)-3,4-dihydro-2(1H)-carbostyril, and then the carteolol hydrochloride is obtained. Furthermore, the invention provides the carteolol hydrochloride crude medicine obtained according to the method, the eye medicine combination prepared by using the obtained carteolol hydrochloride as the crude medicine, and applications of the obtained carteolol hydrochloride to preparation of drugs for treating or preventing glaucoma or ocular hypertension. The method has excellent pharmaceutical characteristics, for example, the obtained crude medicine and a preparation has excellent stability.