Tridecanoic acid → Methyl 4-tridecanoylpyrrole-2-carboxylate

Beteiligte Stoffe

Reaktionsschritte

In 480 ml of methylene chloride, were dissolved 102.9 g (0.48 mol) of tridecanoic acid, to which 52.6 ml (0.72 mol) of thionyl chloride and 0.2 ml of N,N-dimethylformamide were added to obtain a solution. The solution was allowed to stand over night and was evaporated under a reduced pressure. The remaining oil was added to 400 ml of methylene chloride containing 106.6 g (0.8 mol) of anhydrous aluminum chloride, to which 200 ml of methylene chloride solution containing 50.05 g (0.4 mol) of methyl pyrrole-2-carboxylate was added dropwise in 40 minutes at a temperature of 3° to 9° C. After the addition, the temperature of the mixture was elevated slowly up to room temperature and the mixture was stirred for 2 hours. Then, the mixture was poured into 800 ml of ice-water, and 1000 ml of methylene chloride was added thereto to dissolve all the crystals precipitated, followed by liquid separation. The organic layer was washed with water three times, dried over anhydrous magnesium sulfate and condensed under a reduced pressure. The residue was recrystallized from 400 ml of ethyl acetate and 400 ml of hexane to obtain 107.2 g of methyl 4-tridecanoylpyrrole-2-carboxylate as white crystals. The yield was 83% and the melting point was 92° to 93° C.

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