Über die Begleitalkaloide des Morphins. VII

Abstract

3‐Methoxy‐4,5‐methylendioxy‐β‐phenyläthylamin 5 und Mekonin‐3‐carbonsäurechlorid 6 wurden nach bekannten Synthesewegen hergestellt. Das durch Kondensation von 5 und 6 gewonnene Säureamid 7 wurde nach der BISCHLER‐NAPIERALSKI‐Methode zum Ring geschlossen. Durch Reduktion des erhaltenen Gemisches von 8 und 9 konnte Norgnoscopin 10 gewonnen werden. 10 wurde nach der ESCHWEILER‐CLARKE‐Methode zu Gnoscopin 3 methyliert.

Synthesis of phthalideisoquinolines from 3-halophthamdes and 3,4-dihydroisoquinolinium salts

“…In the interim, but particularly in the past decade, many new but less direct approaches to the construction of this ring system have been reported (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). In the past year, two syntheses using the strategy of Perkin and Robinson have been reported in which improved methods of joining the two moieties have been developed.…”

(-)-β-Narcotine: A Facile Synthesis and the Degradation with Ethyl Choroformate

“…Fine aluminum foils (1 g, 99.999%, Aldrich) in methanol (10 mL) were refluxed with mercuric chloride (6 g Preparation of deuterated (-)-β β β β-narcotine (7). 7 was prepared according to the above procedure using CH 3 Degradation of β β β β-narcotine (6) with ethyl chloroformate. 6 (4.13 g, 0.01 mol) was dissolved in methylene chloride (10 mL) and stirred with ethyl chloroformate (4 mL, 0.04 mol) at room temperature for 5 h. The solvent and the excess reagent were thoroughly removed to afford the crude product, which was immediately subjected to column chromatography with 4 : 1 CHCl 3 /ether for isolation of the intermediate chloro-carbamate (6b).…”

“…1 A few years later, this group had firstly synthesized β-narcotine (6) with contarnine (1) and nitromeconine in five steps, which resulted in poor yields. 2 Although some advanced methods for the preparation of α-narcotine have been developed using modified Bischler-Napieralski cyclization, 3,4 the facile synthesis of β-narcotine has not further been attempted, supposingly because of its no clinical efficacy contrary to α-narcotine. We could conveniently prepare β-narcotine (6) by aromatic iodination using cotarnine (1) as a starting material.…”

An Acid-Catalyzed Epoxide Ring-Opening/Transesterification Cascade Cyclization to Diastereoselective Syntheses of (±)-β-Noscapine and (±)-β-Hydrastine

“…Clinically used ( – )-α-1 can be provided through extraction from plant resources . For the intriguing structure and important bioactivity, Noscapine ( 1 ) has become an attractive target for chemical synthesis and much effort has been made toward the development of efficient routes to Noscapine ( 1 ). ,− The first route was reported by Robinson and Perkin, who constructed a C-1–C-3′ bond through direct condensation between Cortanine and Meconine, which were produced by degradation of natural ( – )-α-1 . Based on Robinson–Perkin strategy, several other approaches , were reported, such as zinc-promoted coupling and electrochemical reductive coupling …”

“…Alternatively, Kerekes and Bognár and Szántay et al synthesized phthalide isoquinoline skeletons through the Bischler–Napieralski reaction. Despite these remarkable achievements, an inherent drawback associated with all of the above-mentioned strategies was the lack of regioselectivity and/or stereoselectivity.…”