http://www.orgsyn.org/orgsyn/prep.asp?prep=cv5p0139 (http://www.orgsyn.org/orgsyn/prep.asp?prep=cv5p0139)
at rhodium's page for the conversion of phenylamines to benzaldehydes via the diazonium salt. Can the diazonium salt be oxidised, say with O3, permanganate, or H2O2, to the nitro compound? Is the diazo group stablizied by its proximity to the benzene ring, such that a similiar reaction could not be performed on ethyl amine? (Oh, or methylamine, with intent to react as reported to acetaldehyde?)(EDIT: The diazonium salt formation also requires NaNO2 unfortunately, but in a 1:1 molar ration with substrate. If the proposed route above worked and turned out to be very efficient, this wouldn't be a problem. Otherwise, probably not worth it.)