Methanol → Methyl 5-methyl-2-thiophenecarboxylate

Participants

Reaction Steps

Add thionyl chloride (153 ml, 2.1 mol) dropwise over 20 min to a solution of 5-methylthiophene-2-carboxylic acid (100 g, 0.703 mol) in MeOH (1 L) at 0° C. and stir. After the addition is complete, heat the reaction mixture to reflux for 3.5 hours. Cool and concentrate in vacuo to give a thick oil. Dilute the oil with EtOAc (500 ml) and sequentially wash with water (300 ml) then brine (300 ml). Dry the organic layer over sodium sulfate. Remove the solids by filtration. Collect the filtrate and concentrate under reduced pressure to give the title compound (106 g, 97%), which is used without further purification. ESI (m/z) 156(M+H).

Provenance & Evidence