Hydrogen Sulfide → 4-Aminobenzaldehyde

Participants

Reaction Steps

Still another object of this invention is to provide a novel process for producing p-hydroxybenzaldehyde through p-aminobenzaldehyde from p-nitrotoluene. This process comprises reacting p-nitrotoluene with sodium polysulphide prepared by reacting sodium hydroxide with hydrogen sulphide and incorporating the resulting sodium hydrosulphide with sodium hydroxide and then with sulphur, in the presence or absence of an aprotic polar compound in a mixed solvent consisting of an alcohol and an aqueous alkali solution to produce p-aminobenzaldehyde, adding the thus produced p-aminobenzaldehyde to an aqueous solution, preferably a 2-50 wt.% aqueous solution of sulphuric acid at 60°-100° C., preferably 75°-90° C., to produce the sulphate thereof rapidly, diazotizing (after cooling) the thus produced sulphate to obtain a diazonium salt of p-aminobenzaldehyde and then hydrolyzing the thus obtained diazonium salt in water or an aqueous solution of sulphuric acid at 70°-100° C. to obtain p-hydroxybenzaldehyde.

Provenance & Evidence