1-Phenyl-2-propyn-1-ol

100-52-7

74-86-2

4187-87-5

The general procedure for the synthesis of (±)-1-phenyl-2-propyn-1-ol from benzaldehyde and acetylene was as follows: magnesium (518 mg, 28.3 mmol) was placed in a pre-flame-dried, two-necked, round-bottomed flask fitted with a reflux condenser and cooled to room temperature under argon atmosphere. Subsequently, tetrahydrofuran (30 mL) and a small amount of iodine crystals were added. Next, a portion of the total volume of n-butyl chloride (2.23 mL, 28.3 mmol) was added dropwise and the mixture was refluxed until the Grignard reagent was generated. After removing the unreacted n-butyl chloride, the remaining n-butyl chloride was added. Stirring was continued at room temperature until all the magnesium was consumed. The reaction mixture was cooled to 0°C and acetylene gas was passed into it over a period of 15 minutes. Subsequently, benzaldehyde (1.0 g, 9.4 mmol) dissolved in tetrahydrofuran (20 mL) was added at 0°C and stirred for 6 hours. Upon completion of the reaction, the reaction was quenched with saturated ammonium chloride solution, diluted with water and extracted with ethyl acetate. The organic layers were combined, dried with anhydrous sodium sulfate, concentrated and purified by silica gel column chromatography (eluent 10% petroleum ether solution of ethyl acetate) to afford the target product (±)-1-phenyl-2-propyn-1-ol (1.08 g, 86% yield) as a pale yellow oil.