Synthesis of carboxylic acid esters

A process for the preparation of carboxylic acid esters having the formula RCOOR.sub.3 from carboxylic acid amides having the formula RCONR.sub.1 R.sub.2 and hydroxyl compounds having the formula R.sub.3 OH, which comprises contacting at least one mole of said hydroxyl compound with each mole of said amide in the vapor phase at temperatures of from 100.degree. C. to 400.degree. C. and at pressures of from 0.01 to 100 atmospheres in the presence of a solid catalyst having a surface area of 10 to 1000 m.sup.2 /g for a contact time of 0.1 to 20 seconds, thereby forming the ester and HNR.sub.1 R.sub.2, recovering the ester by condensation of the exit vapors by cooling, and separating HNR.sub.1 R.sub.2 from the uncondensed portion of the exit vapors, wherein

• R is selected from the class consisting of H;
• an alkyl group having from 1 to 10 carbon atoms;
• an alkenyl group having from 2 to 10 carbon atoms;
• alkynyl having from 2 to 10 carbon atoms;
• phenyl;
• and a phenyl group substituted by a methyl, chloro or methoxy group;
• R.sub.1 taken separately is selected from the class consisting of H and alkyl groups having from 1 to 10 carbon atoms;
• R.sub.2 taken separately is selected from the class consisting of H and alkyl groups having from 1 to 10 carbon atoms;
• R.sub.3 is selected from the class consisting of
• primary or secondary alkyl group having from 1 to 10 carbon atoms;
• primary or secondary alkyl group having from 2 to 10 carbon atoms substituted by a hydroxy group, alkoxy group having from 1 to 4 carbon atoms or an acetoxy group;
• phenyl;
• and
• phenyl substituted by 1 or 2 alkyl groups having 1 to 10 carbon atoms, 1 or 2 fluorine atoms, 1 or 2 chlorine atoms, 1 or 2 bromine atoms, a methoxy group or a methoxycarbonyl group;
• and the catalyst is selected from the class consisting of titanium dioxide, alumina, zirconium oxide, molybdena, cerium (IV) oxide, mixtures of from 10 to 100% alumina and 90 to 0% silica, mixtures of from 0 to 100% titanium dioxide and 100 to 0% alumina, and supported catalyst compositions comprising 5 to 25% vanadium pentoxide, nickel oxide, or tungsten oxide on alumina, alumina-silica mixtures, or copper (II) oxide and chromium (III) oxide mixtures.