| 摘要 |
<p>PURPOSE:To obtain the titled compound in high yield in short reaction steps, by preparing a Grignard reagent from an easily available p-chloroprenylbenzene as a raw material with metallic magnesium, and reacting the resultant Grignard reagent with acetaldehyde. CONSTITUTION:p-Dichlorobenzene of formulaIis reacted with metallic magnesium in a solvent, and then reacted with a prenyl halide of formula II to afford p-chloroprenylbenzene of formula III easily in high yield. The resultant compound of formula III is then reacted with metallic magnesium in an amount of 0.8- 1.5 atomic equivalents based on the compound of formula III in a solvent, e.g. tetrahydrofuran, preferably in the presence of a small amount of I2, CH3Br, etc. for activating the Mg at 100-150 deg.C to prepare a Grignard reagent, which is then racted with acetaldehyde of formula IV at -40-+20 deg.C to afford the aimed compound of formula V useful as an intermediate for 2-(p-prenylphenyl) propionic acid having anti-inflammatory and analgesic actions.</p> |
