Acetic acid, 2,2-dimethoxy-, methyl ester → HCID 67338446, compound

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Reaction Steps

A mixture of 2-amino-3-benzylpyridine (18.3 g, 99.4 mmol; crude) and methyl 2,2-dimethoxyacetate (22 g, 21.6 mmol, 1.9 eq.) in a 250 ml round-bottomed flask was treated at room temperature with concentrated, sulphuric acid (50 ml) by quick addition while stirring. A vigorous exothermic reaction took place. After stirring for 30 minutes the dark mixture was poured on ice water (1000 ml). Concentrated ammonia (25% aq.; 250 ml) was added to basify the mixture. Extraction with dichloromethane (2×150 ml). The combined organic layers were dried with Na2SO4. Evaporation under vacuum gave 10,11-dihydro-5H-benzo[e]pyrido[2,3-b]azepine-10-carboxylic acid methyl ester as a yellow foam (18.5 g, 72.8 mmol) in 73% yield. An analytically pure sample can be obtained by chromatography on silica gel. Rf=0.3 (EtOAc/n-heptane=1:1).

Provenance & Evidence