Water → 2-(2-tert-Butoxycarbonylamino-pyridin-4-ylmethylene)-succinic acid 4-benzyl ester 1-tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Butyllithium (1.6 M in hexane, 14.8 ml, 23.7 mmol) was added dropwise to a solution of 2-(diethoxy-phosphoryl)-succinic acid 4-benzyl ester 1-tert-butyl ester (9.50 g, 23.7 mmol in THF (75 mL) at 0° C. under nitrogen. After stirring at 0° C. for 1 h, the solution was transferred to a solution of (4-Formyl-pyridin-2-yl)-carbamic acid tert-butyl ester (3.70 g, 16.6 mmol) in THF (75 mL). The resulting reaction mixture was stirred at 0° C. for 1 h before being allowed to warm to 25° C., and the mixture was stirred overnight. Water (400 mL) was added and the product extracted with CH2Cl2 (3×50 mL). The combined organic layers were dried and concentrated. Flash chromatography (hexane/EtOAc, 4:1) gave 2-(2-tert-Butoxycarbonylamino-pyridin-4-ylmethylene)-succinic acid 4-benzyl ester 1-tert-butyl ester 4.30 g (55%).

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