Synlett 2006(1): 0153-0154  
DOI: 10.1055/s-2005-922781
SPOTLIGHT
© Georg Thieme Verlag Stuttgart · New York

Sodium Nitrite (NaNO2)

Dan Bernardi*
Faculté des Sciences, Université Paul Verlaine-Metz, 1 Bld Arago, 57078 Metz Cedex 3, France
e-Mail: dan.bernardi@umail.univ-metz.fr;
Further Information

Publication History

Publication Date:
16 December 2005 (online)

Introduction

The well-known NaNO2 (mp 271 °C, d = 2.17) has ­multiple applications in organic synthesis but also in ­medicine as a vasodilator, bronchodilator and antidote against cyanide and H2S poisoning. It is produced in the human body from saliva and sodium nitrate to control bacteria in the stomach.

The synthetic utilities of NaNO2 have been extensively investigated in organic chemistry. Nitrosation of primary amines with nitrous acid (generated in situ from sodium nitrite and a strong acid) leads to diazonium salts. These salts are useful synthetic intermediates used in named ­reactions like Sandmeyer, Balz-Schiemann, [1] Pschorr, [2] and Heck [3] or in the manufacture of diazo dyes. [4] NaNO2 is also used in the synthesis of alkyl nitrites, [5] reagents used for the synthesis of diazonium salts in non-aqueous media [6] or for the diazotization of primary aliphatic amines [7] in DMF.

NaNO2 reacts with SO2 and potassium hydrogen carbonate to afford potassium hydroxylaminedisulfonate salt, which gives after oxidation nitrosodisulfonic acid di­potassium salt. This Fremy’s salt is a useful reagent for the selective oxidation of phenols and aromatic amines to quinones (the Teuber reaction). [8]

Hydroxylamine hydrochloride is synthesized from NaNO2 in a three-step procedure. [9]