Hydrazine hydrate (1:1) → Dimethyl 2-aminomethyl-2-(4-tert-butoxycarbonylpiperazin-1-yl)malonate

Participants

Reaction Conditions

Reaction Steps

A solution of 2.9 ml (64 mmol) of hydrazine hydrate in 8 ml of methanol is added to a solution of 27.5 g (58 mmol) of dimethyl 2-(4-tert-butoxycarbonylpiperazin-1-yl)-2-(1,3-dioxo-1,3-dihydroisoindol-2-ylmethyl)malonate in 300 ml of methanol cooled beforehand to −5° C. The reaction medium is stirred at from −5° C. to ambient temperature over the course of 3 h. After evaporation and addition of 300 ml of water, the reaction medium is extracted with ethyl acetate. The organic phases are washed with a saturated aqueous solution of sodium hydrogen carbonate, dried over magnesium sulfate, filtered and evaporated. The residue obtained is purified by chromatography on silica gel, elution being carried out with an 8/2 heptane/ethyl acetate mixture and then an increase in polarity up to a 90/10 ethyl acetate/methanol mixture. 10 g (50%) of dimethyl 2-aminomethyl-2-(4-tert-butoxycarbonylpiperazin-1-yl)malonate are thus obtained in the form of a light oil.

Provenance & Evidence