Process for producing aldehydes

A process for selectively producing aldehydes which comprises introducing into a reaction zone (1) methanol, (2) carbon monoxide, (3) hydrogen, (4) cobalt, (5) iodine, and (6) a phosphorus-containing ligand defined by the following formula:

• ##STR4## wherein R.sub.1, R.sub.2 and R.sub.5 are either alike or different members selected from the group consisting of alkyl radicals having from one to 24 carbon atoms, aryl radicals having from six to 20 carbon atoms, alkenyl radicals having from two to 30 carbon atoms, cycloalkyl radicals having from three to 40 carbon atoms, cycloalkyl radicals having from three to 40 carbon atoms, aralkyl and alkaryl radicals having from six to 40 carbon atoms and dihydrocarbyl phosphino alkyl radicals, R.sub.3 and R.sub.4 are either alike or different members selected from the group consisting of hydrogen, alkyl radicals having from one to 24 carbon atoms, aryl radicals having from six to 20 carbon atoms, alkenyl radicals having from two to 30 carbon atoms, cycloalkyl radicals having from three to 40 carbon atoms, aralkyl and alkaryl radicals having from six to 40 carbon atoms, and dihydrocarbyl phosphino alkyl radicals, E is phosphorus, n is an integer ranging from 1 to 3, and x can be 1 to 3, the molar ratio of carbon monoxide to hydrogen being in the range of about 2:1 to about 1:2, the molar ratio of cobalt to said ligand being in the range of about 1:2 to about 7:1, the molar ratio of cobalt to iodine being in the range of about 1:1.15 to about 1:15, and the weight percent of combined cobalt and iodine, based on the methanol, being in the range of about 0.01 to about ten percent, and then subjecting said contents to an elevated temperature of about 150.degree. to about 250.degree. C. and an elevated pressure of at least about 2200 pounds per square inch for about five minutes to about five hours, sufficient to convert methanol to a product predominating in aldehydes.