50461-24-0

Upstream product

• 124293-98-7 1-(2'-bromo-4',5'-dimethoxybenzyl)-2-ethoxycarbonyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 
• 15366-08-2 s-butylmagnesium chloride 
• 155263-75-5 1-(2'-bromo-3',4'-dimethoxybenzyl)-2-ethoxycarbonyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 
• 247579-49-3 1-(2'-bromo-3',4'-dimethoxybenzyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 

Downstream Products

• 1699-51-0 laudanosine 

Relevant academic research and scientific papers

Radical cyclization to aporphines. A new, efficient total synthesis of the aporphine glaucine and the 4,5-dioxoaporphine pontevedrine, and the first total synthesis of 5-oxoaporphines

We describe the radical cyclization of bromobenzylisoquinolines and benzylisoquinolin-3-ones, which afford aporphines or the novel 5-oxoaporphines and 5-oxodehydroaporphines respectively. Oxidation of the latter compounds provides a new route to 4,5-dioxoaporphines.

A variation of the Pictet-Spengler reaction via a sequential reduction-cyclization reaction of N-acylcarbamates: synthesis of 1-substituted tetrahydroisoquinoline derivatives

A new variation of the Pictet-Spengler reaction for the synthesis of 1-substituted tetrahydroisoquinoline derivatives has been developed. The reaction employs the reduction of N-acylcarbamates by DIBAL-H followed by simultaneous cyclization mediated by BF3·OEt2. The synthetic potential of this method has been illustrated by the synthesis of the tetrahydroisoquinoline alkaloids, (±)-xylopinine, (±)-laudanosine, (±)-8-oxo-O-methylbharatamine, and (±)-isoindoloisoquinolone.

Benzolactams. 4. Reaction of 3′,4′- or 4′,5′-Dialkoxy-Substituted 1-(2′-Bromobenzyl)-2-ethoxycarbonyl-1,2,3,4-tetrahydroisoquinolines with Alkyllithium. 1,2 and 1,4 Additions of Alkyllithium to Benzolactams

Treatment of 1-(2′-bromo-3′,4′-dialkoxybenzyl)-1,2,3,4- tetrahydroisoquinoline carbamates, 1a,c, with excess alkyllithium gave 8-oxoberbines, 2a,c, which were successively attacked in situ with another molecule of alkyllithium to give 1,2 and/or 1,4 addition products. A primary alkyllithium, such as MeLi or BuLi, gave a 1,2 addition product, 8-methyleneberbine 9a or 8-butylideneberbine 3a. t-BuLi preferred 1,4 addition, followed by elimination of the alkoxy group, to give 9-tert-butyl-8-oxoberbine 6a or 7c. s-BuLi gave a mixture of 1,2 and 1,4 addition products, 1-[2′-(2″-methylbutyryl)benzyl]-1,2,3,4-tetrahydroisoquinoline 4a and 9-s-butyl-8-oxoberbine 5a. Similar treatments of carbamate 1b having no alkoxy group at its 3′ position gave 1,2 addition products, 8-butylideneberbine 3b, 1-[2′-(2″-methylbutyryl)benzyl]-1,2,3,4-tetrahydroisoquinoline 4b, and 1-(2′-pivaloylbenzyl)-1,2,3,4-tetrahydroisoquinoline 6b, in all cases. Reactions of 1a with s-BuMgCl and isoPrMgCl also gave the 1,4 adduct, 5a, and its 9-isoPr analogue, 12a. Treatment of 9a with excess NaBH4 in AcOH gave (±)-coralydine (10b).

PHOTOCHEMICAL SYNTHESIS OF APORPHINES: (+/-)-GLAUCINE, (+/-)-NORGLAUCINE AND (+/-)-DEHYDRONORGLAUCINE

Photochemical cyclization of 3 afforded 5, 4 and 8. 5 on LAH reduction furnished (+/-)-glaucine (6) and on treatment with ethanolic HCl afforded (+/-)-norglaucine (7). 10 obtained by the photocyclization of 9 was converted into 7 and 11 via 12.