Bucherer reaction, aminonaphthalene

This reaction was first reported by Bucherer in 1906. It is the synthesis of carbazoles from aryl hydrazines, sodium bisulfite, and 1- or 2-naphthols (or 1- or 2-naphthylamines) and is generally known as the Bucherer carbazole synthesis or Bucherer reaction. In addition, the reaction between 2-aminonaphthalene-l-sulfonic acid and phenylhydrazine also gives carbazole, indicating that sulfonation of naphthylamine might be the early step in the reaction pathway. This reaction has been most commonly used hitherto for the preparation of dibenzocarboles. ... 

Nevile-Winther acid can also be obtained by a reversed Bucherer reaction from l-aminonaphthalene-4-sulfonic acid with aqueous sodium hydrogen sulfite solution and SO2 at 95 °C and a pressure of 2.5 bar. 

Canete, A. Melendrez, M. X. Saitz, C. Zanocco, A. L. Synthesis of aminonaphthalene derivatives using the Bucherer reaction under microwave irradiation. Synth. Commun. 2001, 31, 2143-2148. 

Scheme 835. A possible path for the amiaolysis of P-naphthol (the Bucherer reaction or the Budierer-LePetit reaction). It is suggested that bisulfite adds to the aromatic ring, the phenolic hydroxyl tautomerizes, an addition reaction of ammonia to the carbonyl carbon occurs with loss of water, and, finally, the imine so generated tautomerizes, bisulfite is lost, and the aminonaphthalene is produced.

Figure 2.20). Desulphonation of both tetralone compounds in the 3-position is effected by dilute HCl. It should be noted that the term Bucherer reaction applies equally to the conversion of NH2- OH and vice-versa. 1-Aminonaphthalene derivatives are shown in Figure 2.21 and Table 2.14, and H acid (l-amino-8-hydroxynaphthalene-3,6-disulphonic acid) and related intermediates in Figure 2.22 and Table 2.15. 

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