反应详情

To a stirred solution of (8) (1.0 g, 2.22 mM) in methanol (100 mL) is added 1 mL of water followed by dropwise addition of 2.5 N sodium hydroxide solution (4.0 mL). The walls of the reaction flask are rinsed down with 10 mL of methanol and the mixture is stirred under a nitrogen atmosphere until TLC analysis shows no ester (mono- or di-) remaining. The methanol is removed in vacuo, the residue taken up in 100 mL of water, stirred for solution, filtered (20 mL water rinses), and the stirred filtrate acidified dropwise with 2 N hydrochloric acid. Filtration of the resultant precipitate followed by copious water washing and drying gave 0.87 g (96%) of (9) as a chalk-like white solid. The compound was one component by TLC (silica gel, the eluant was 10 mL of 2% methanol in methylene chloride containing 4 drops of glacial acetic acid). mp 128.5-130° C. uncorr.

1. washThe walls of the reaction flask are rinsed down with 10 mL of methanol
2. customThe methanol is removed in vacuo
3. stirringstirred for solution
4. filtrationfiltered (20 mL water rinses)
5. filtrationFiltration of the resultant precipitate
6. customdrying