Prepd by reduction of nitrobenzene with sodium arsenite: Bigelow, Palmer, Org. Synth. coll. vol. II, 57 (1943); also by treatment of nitrobenzene with glucose in alkaline medium: Opolonick, Ind. Eng. Chem. 27, 1045 (1935). Industrial prepn by heating nitrobenzene with molasses and NaOH in high flash naphtha: DE 228722. Also prepd by catalytic reduction of nitrobenzene: Busch, Schulz, Ber. 62, 1458 (1929). By peracetic acid oxidation of azobenzene: D'Ans, Kneip, Ber. 48, 1145 (1915); cf. Greenspan, Ind. Eng. Chem. 39, 847 (1947). Prepn of cis- and trans-forms by perbenzoic acid oxidation of azobenzene: G. M. Badger et al., J. Chem. Soc. 1953, 2143.