Trimethylsilyldiazomethane → 1-tert-butyl 2-methyl (2S,4R)-4-[(7-bromo-6-methoxyisoquinolin-1-yl)oxy]pyrrolidine-1,2-dicarboxylate

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Reaction Steps

To a solution of compound 122 in MeOH (0.1 M) was added TMS-diazomethane (4.2 eq.) and the mixture was stirred at RT for 20 min. Volatiles were evaporated and the crude purified by chromatography to obtain 1-tert-butyl 2-methyl (2S,4R)-4-[(7-bromo-6-methoxyisoquinolin-1-yl)oxy]pyrrolidine-1,2-dicarboxylate as a pale orange foam (79%). To the previous compound dissolved in toluene (0.1 M) tetrakis-(triphenylphospin)-palladium(0) (0.1 eq.) and vinyltri-N-butyltin (1 eq) were added and the mixture was heated at 100° C. for 20 h. Volatiles were evaporated and the residue purified by chromatography to obtain 1-tert-butyl 2-methyl (2S,4R)-4-[(6-methoxy-7-vinylisoquinolin-1-yl)oxy]pyrrolidine-1,2-dicarboxylate as a pale yellow foam (45%) that was treated with HCl 4N in dioxane (26 eq) at RT. After 30 min volatiles were evaporated to obtain the title compound 123 in quantitative yield. MS (ES+) m/z 329 (M+H)+.

Provenance & Evidence