2-Amino-3-pyridinecarboxaldehyde

Chemical Properties

yellow crystals

Uses

2-Aminonicotinaldehyde is commonly employed as a starting material for a wide variety of N-heterocyclic compounds (e.g. β-nicotyrine [N445000]) . 2-Aminonicotinaldehyde is also used as a reagent to synthesize hydrazones (e.g.thionaphthenquinone 3-hydrazone [T367720]), which possess antituburcular properties.

Preparation

Preparative Methods of 2-Amino-3-pyridinecarboxaldehyde: the reagent is best when freshly prepared. A multistep procedure starting from 2-amino-3- picoline has been improved upon by a simple two-step approach. Sulfamation of nicotinamide with ammonium sulfamate (both commercially available) provides 2-(3′-pyridyl)pyrido[2,3-d]pyridimine which may be hydrolyzed in 2 N HCl to provide the reagent (eq 1)^[1]. Substituted derivatives of the reagent may be prepared via a similar intermediate.

Synthesis

General procedure for the synthesis of 2-amino-3-pyridinecarboxaldehyde from the compound (CAS: 7521-27-9): first, a 2 mol/L hydrochloric acid solution was prepared. The dried feedstock was transferred to a 50 mL single neck flask and about 30 mL of the above hydrochloric acid solution was added. The mixture was heated to reflux for 4 hours and subsequently cooled to room temperature. The pH of the reaction mixture was adjusted to 7-8 using 10 mol/L sodium hydroxide solution. 5 extractions were carried out with ether and the organic phases were combined and dried over anhydrous potassium carbonate. The solvent was removed by rotary evaporation to give a yellow solid product. Finally, it was purified by column chromatography (unfolding agent ratio VD TM/VEIQH = 30:1) and dried at low temperature to obtain pure 2-amino-3-pyridinecarboxaldehyde in light yellow color in 30% yield.

storage

2-Amino-3-pyridinecarboxaldehyde is somewhat more stable than 2-Aminobenzaldehyde and may be stored for up to several months at 0 °C under an inert atmosphere. Sublimation is a convenient method for the separation of higher oligomers which may accumulate during storage. Use in a fume hood.

References

1. (a) Caluwe, P. T 1980, 36, 2359. (b) Cheng, C.-C.; Yan, S.-J. OR 1982, 28, 37. (c) Thummel, R. P. SL 1992, 1.