O-Cresol → (E)-3-o-tolyloxy-but-2-enoic acid ethyl ester

Participants

Reaction Steps

To a stirred mixture of 2-methyl-phenol (4.90 g, 0.045 mol) and ethyl-2-butynoate (10.1 g, 0.09 mol) in tetrahydrofuran (15 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (6.80 g, 0.045 mol) slowly. After addition was complete the mixture was stirred at reflux for 6 h. Upon completion of the reaction the tetrahydrofuran was removed in vacuo and the residue was diluted in diethyl ether and washed first with 1N aqueous hydrochloric acid, then 10% aqueous sodium hydroxide solution, a saturated sodium chloride solution and dried over magnesium sulfate. The crude product, (E)-3-o-tolyloxy-but-2-enoic acid ethyl ester, was obtained as a brown oil (6.45 g, 65%) and used without further purification.

Provenance & Evidence