Isoquinoline-5,8-diones synthesis

Isoquinoline-l,3-dione, 5,6,7,8-tetrahydro-synthesis, 2, 408 Isoquinoline hydrobromide bromination, 2, 49 Isoquinolines adducts... 

Substituted 4-aryl-1 -oxo-1,2-dihydropyrazino[l, 2-i]isoquinolinium salts 402 were obtained when 3-substituted isoquinolines 401 were cleaved from a polymer by treatment 25% TFA (00MIP5). c/i-3,lla-H-3-Phenyl-1,2,3,4,11,11 fl-hexahydropyrazino[l, 2-i]isoquinoline-1,4-dione (404) formed when isoquinoline derivative 403 was cleaved from a resin with 25% TFA during an automated solid-phase synthesis (98BMCL2369). 

Depending on the reaction temperature and reaction time, tetrahydroisoquinoline 357 afforded different mixtures of 1,2,3,4,11,11 a-hcxahydro-6//-pyrazino[ 1,2-3]isoquinolines 358-361 and tetracyclic compound 362 (Scheme 30) <2005JA16796>. Each of the individual diastereoisomers 358-361 could be transformed into the compound 362. z7r-3//,4a//-3-Phcnylpcrhydropyra/ino[ 1,2-7]isoquinoline-l,4-dione was prepared via automated parallel solid-phase synthesis on Kaiser oxime resin <1998BML2369>. l,2,3,5,6,7-Hexahydropyrido[l,2,3-r/f ]quinoxaline-2,5-dionc was obtained by catalytic hydrogenation of ethyl 3-(2-oxo-l,2,3,4-tetrahydro-5-quinoxalinyl)acrylate in the presence of TsOH over 5% Pd/C catalyst under 40 psi of hydrogen <1996JME4654>. 

Monsal and coworkers have achieved the construction of pyrrolidine nucleus in the synthesis of tetrahy-dropyrrolo[3, 4 3.4]pyrrolo[2.1-fl]isoquinoline-9,ll-diones 57 derivatives in an aqueous micellar medium [53]. The S5mthesis involves a one-pot three-component reaction of variously substituted isoquinolines 54, 2-bromoacetophenone 55, and N-arylmaleimide derivatives 56 in the presence of triethylamine as a base (Scheme 18). The preliminary investigation indicated that the presence of surfactant was essential for the success of reaction. Accordingly, the reactions were carried out in cationic, anionic, and nonionic surfactants well above their critical micelle concentrations (CMC). The maximum yields were obtained in cetyltrimethylammonium bromide (CTAB) (CTABiCMC value 0.29 mM at 80mM concentration). The mechanism of formation involves an in situ generation of isoquinolinium ylides followed by [2 -h3] cycloaddition of N-aryl maleimides. 

Palladium-Catalyzed Heteroqfclic Synthesis via Carbonylative C-H Activation 477 Table 15.9 Selected examples for the carbonylative isoquinoline-1,3(2H,4H)-dione... 

Kobayashi, K., Takanohashi, A., Watanabe, S., Morikawa, O., and Konishi, H., One-pot synthesis of isoquinoline-5,8-dione derivatives from acylquinones and enamines. Tetrahedron Lett., 41, 7657-7660, 2000. 

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