Isobutyric anhydride prodn. from propylene - by carbonylation in liq. hydrogen fluoride and hydrolysis of prod.

摘要

Prodn of isobutyric anhydride (I) is carried out by (a) carbonylating propylene in the presence of excess anhydrous liq HF; (b) fractionating the reaction mixt to separate isobutyryl fluoride (II) and recover unreacted HF for recycle; (c) hydrolysing (II) at 0-100 deg C in the presence of an HF acceptor (III) and 0.05-0.5 mole of water per mole of (II), the water being completely consumed in the reaction to form an equilibrium reaction mixt including a liq phase comprising (I) and (II) and a solid phase comprising an HF/(III)complex; and (d) fractionating the liq phase to give a prod fraction comprising (I) and an overhead fraction comprising (II) for recycle to step (c). The process avoids problems associated with the sepn of (I) from HF; recycle HF can be recovered from the HF/(III) complex.