Triethylamine → Dimethyl 2-(4-tert-butoxycarbonylpiperazin-1-yl)-2-[(4-but-2-ynyloxybenzoylamino)methyl]malonate

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Reaction Steps

2 ml (14.2 mmol) of triethylamine then 2.9 g (14.2 mmol) of 4-but-2-ynyloxybenzoyl chloride diluted in 30 ml of tetrahydrofuran are added to a solution of 4 g (11.6 mmol) of dimethyl 2-aminomethyl-2-(4-tert-butoxycarbonylpiperazin-1-yl)malonate (prepared as described in example 1-3) in 40 ml of tetrahydrofuran. The reaction medium is stirred at ambient temperature for 1 h, then hydrolysed and the product is extracted with ethyl acetate. The organic phase is washed with water then with a saturated aqueous solution of sodium chloride, dried over magnesium sulphate, filtered and concentrated. The crude product obtained is purified by chromatography over silica gel eluted with a 5/5 heptane/ethyl acetate mixture. 4.2 g (70%) of dimethyl 2-(4-tert-butoxycarbonylpiperazin-1-yl)-2-[(4-but-2-ynyloxybenzoylamino)methyl]malonate are obtained in the form of a beige solid.

Provenance & Evidence