N,N'-di-Boc-2-methanesulfonyloxy-1,3-diaminopropane → di-tert-butyl [2-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-1,3-propanediyl]biscarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-[(tert-butoxycarbonyl)amino]-1-{[(tert-butoxycarbonyl)amino]methyl}ethyl methanesulfonate (200 g) was added phthalimide potassium salt (101 g), and the mixture was stirred overnight at 75° C. To the reaction mixture was added water (6 L), and the mixture was extracted with ethyl acetate (6 L). The organic layer was washed with water (1.5 L×3) and brine, and dried over anhydrous magnesium sulfate. Concentration under reduced pressure gave a residue, which was triturated with hexane (500 ml). The collected crystals was washed with hexane (100 ml×3), and the mother liquor was recrystallized from hexane (300 ml) and combined with the former crystals to give di-tert-butyl [2-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-1,3-propanediyl]biscarbamate (168 g).

Provenance & Evidence