2-Amino-6-bromothiazolo[5,4-b]pyridine

Uses

2-Amino-6-bromothiazo[5,4-B]pyridine is an organic intermediate that can be prepared in one step from 5-bromo-2-chloropyridine-3-amine and potassium thiocyanate, or in three steps from 3-amino-5-bromo-2-fluoropyridine and benzoyl isothiocyanate.

Synthesis

General procedure for the synthesis of 2-amino-6-bromothiazolo[5,4-b]pyridin-2-yl from N-(6-bromothiazolo[5,4-b]pyridin-2-yl)benzamide: Dissolve N-(6-bromothiazolo[5,4-b]pyridin-2-yl)benzamide (2.0 g, 5.98 mmol) in 70% sulfuric acid (10.0 mL) and react by heating to 140 °C for 1 hour. Upon completion of the reaction (monitored by TLC), the reaction mixture was poured into crushed ice and the pH was adjusted to 8.0 with 30% aqueous sodium hydroxide, followed by extraction with ethyl acetate (3 x 150 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to afford the target product 2-amino-6-bromothiazolo[5,4-b]pyridine (1.34 g, 98% yield). The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ 7.85 (d, J=2.0 Hz, 1H), 8.05 (br s, 2H), 8.18 (d, J=2.0 Hz, 1H).

References

[1] Patent: WO2009/74812, 2009, A1. Location in patent: Page/Page column 91; 92