Tetrahydrofuran → Ethyl acetate ethanol ammonia

Participants

Reaction Steps

General working instructions 4 (GWI-4): O-(7-Azabenzotriazol-1-yl)N,N,N′,N′-tetramethyluronium hexafluorophosphate (1.1 eq.) and N-ethyl-diisopropylamine (2.5 eq.) were added to a solution of the corresponding carboxylic acid (1 eq.) in tetrahydrofuran at 0° C. and the reaction mixture was stirred at room temperature for 0.5 h. The corresponding amine (1 eq.) was then added and the mixture was stirred at room temperature overnight. For working up, the reaction mixture was diluted with ethyl acetate and washed with sat. NaHCO3 solution, NH4Cl solution, dist. water and sat. NaCl solution. The combined organic phases were dried over sodium sulfate, filtered and concentrated. The crude product was purified by column chromatography (silica; ethyl acetate/ethanol/ammonia (25% aq.) in order to obtain the product (H) in a pure form.

Provenance & Evidence