Carbamate → Carbanilide

Participants

Reaction Steps

In a separate run, the foregoing procedure is repeated except that the charge to the reactor additionally contains 4.0 grams of nitrobenzene. After 19 hours of reaction at a temperature of 180° C. and a CO pressure of 1000 psig, analysis of the reactor effluent from this second run shows methyl-N-phenyl carbamate to be formed in a yield of only 100%, based on cobalt charged, with a selectivity to a carbamate of only 50%, based on cobalt charged. The balance of products is found to comprise predominantly formanilide, with a minor quantity of diphenyl urea also being formed. There is also observed to be formed during the reaction a precipitate comprising Co(OH)2, resulting from the reaction of cobalt with water which is formed in the reaction mixture from --NO2 moieties in the system. The water therefore adversely combines with the cobalt carbonyl and removes the desired catalyst from the reaction.

Provenance & Evidence