PURPOSE: To obtain the titled substance, by reacting CO with water and an acrylic acid ester in the presence of cobalt carbonyl, 1,2-bis(diphenylphosphino) ethane and a nitrile.

CONSTITUTION: In preparing the titled substance by reacting CO with water and an acrylic acid ester, the reaction is carried out in the presence of cobalt carbonyl, 1,2-bis(diphenylphosphino)ethane and a nitrile. A cobalt compound (e.g., cobalt acetate, cobalt oxide) capable of forming cobalt carbonyl under reaction conditions may be used instead of cobalt carbonyl, and the amount of the catalyst used is 3.3W0.005mol% calculated as Co atom baed on acrylic acid ester. A nitrile shown by the formula CH3(CH2)nCN (n is 0W16) or NC(CH2)nCN (n is 1W4) is preferable as the nitrile and the amount of the nitrile used is 1W10 times molar amount as much as that of Co atom. The reaction temperture is 120W160°C.