PROCESS FOR PREPARING ALPHA-(3-BENZYLPHENYL)PROPIONIC ACID DERIVATIVE.

摘要

Alpha-(3-benzylphenyl) propionic acid and its derivatives of formula (I): (where X is OH, H or 1-4C alkoxy) are prepared from the heavy oil fraction obtd. as a by-product in the synthesis of ethylbenzene from benzene by alkylation with ethylene in the presence of synthetic zeolite ZSM-5 as catalyst. The by-product is distilled at 288-295 deg.C to give (3-ethylphenyl) phenylmethane; this is dehydrogenated (pref. at 500-700 deg.C and up to 5 kg/cm2, using a Fe or Cr oxide catalyst) to give (3-vinylphenyl) phenylmethane, which is carbonylated using carbon monoxide at 40-200 deg.C (pref. using a Pd, Pt, Rh, Ir or Ru catalyst), together with hydrogen, water or a lower alkanol to give the appropriate product.