Indoles ester

A remarkably simple fused indole devoid of the traditional side chains is described as an antidepressant agent. Michael addition of the anion from indole ester 119 to acrylonitrile affords the cyanide 120. Selective... 

Hanaoka et al. reported a total synthesis of murrayaquinone A (107) based on an anionic [4+2] cycloaddition of the indole ester 864 with phenyl p-tiimethylsilylvinyl sulfone (865) (631). The reaction of the MOM-protected indole 864 with phenyl... 

Spande, T. E., Edeards, M. W., Pannell, L. K., Daly, J. W., Erspamer, V. and Melchiorri, P. 1988. Pseudophrynamine A An unusual prenylated pyrrol[2,3,-(3]indole ester from an Australian frog, Pseudophryne coriacea (Myobatrachidae). Journal of Organic Chemistry, 53 1222-1226. 

M.D. Truppo, M. Journet, A. Shafree, J.C. Moore, Optimization and scale-up of a lipase-catalyzed enzymatic resolution of an indole ester intermediate for a prostaglandin D2 (DP) receptor antagonist targeting allergic rhinitis, Org. Proc. Res. Dev. 10 (2006) 592. 

A procedure for obtaining indole-3-carboxylate ester from the f-pyrrolidino-o-nitrostyrene intermediates in the Leimgruber-Batcho indole synthesis was demonstrated. Although ethyl chloroformate is evidently not reactive enough, phosgene followed by methanolysis effects f) -carbomethoxylation. Reductive cyclization then gives the indole esters. <95SC95>... 

Also, AMI and N-substituted indole esters (Fig. 3), which were reported to be COX-2 enzyme inhibitors, have inhibitory activity on LP and superoxide anion production [91]. Especially pyrrolidine and o-methylphenyl groups were found to be the most important side chains (Ri group) that elevated both activities for indole esters. 

The only synthetic work in this area reported during the year provides yet more syntheses of the ellipticine ring system. Oikawa and Yonemitsu have applied their carbazole synthesis to a very efficient, if lengthy, preparation of olivacine (191) (Scheme 18) 108 the overall yield of olivacine from the starting indole ester (192) is... 

Chu and coworkers observed that the indole ester (26) can be reduced selectively using pyridine-bo-rane/HCl (equation 81), but Fritz and coworkers found that the same conditions reduce both the indole double bond and the carbonyl group in ketone (27 equation 82) but only the indole double bond in amide (28 equation 83). ... 

The indole esters (91) are not readily enolized and reaction with the lactones (92) regioselectively gives (93 equation 26). ° Similarly, the ester function of the oxazole (94) acts as the electrophile with ethyl acetate giving (95)rather than (96) as was originally thought (equation 27). 

The key steps in this synthesis are the direct formation of the substituted indole ester (11) by the acid-catalysed reaction of ethyl pyruvate with methylphenylhyd-razine, the closure of the tetrahydro- -carboline ring by reaction of (11) with... 

Stevens and colleagues extended the base-promoted reverse-Madelung reaction to a vinylogous version (Scheme 3, equation 1) [22]. Among the many 2-acyl-3-indole esters (and carboxylic acids) that were prepared are 5-7. This clever tactic has been used by Opatz [23, 24] and Webb [25] as summarized in Table 2. Scheme 4 depicts the reaction pathway and includes some of Opatz s examples (8-10). 

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