2-(2,5-DIMETHYL-1H-PYRROL-1-YL)-5-IODOPYRIDINE synthesis

Yield:477889-91-1 90%

Reaction Conditions:

Stage #1: 2-amino-5-iodopyridine;2,5-hexanedionewith toluene-4-sulfonic acid in toluene; for 5 h;
Stage #2: with sodium hydrogencarbonate in water;toluene;

Steps:

20.C

2-Amino-5-iodopyridine (116) (1.0 equiv., 332 mmol, 73.0 g), 2,5-hexanedione(1.2 equiv., 398 mmol, 45.0 g) and/?-toluenesulfonic acid (0.1 equiv., 33 mmol, 5.7 g) were dissolved in toluene (300 ml) and heated in a Dean-Stark apparatus for 5 h. After cooling to room temperature, the dark brown reaction mixture was washed with a saturated aqueous NaHCO₃ solution, water and brine. The organic phase was dried with MgSO₄ and concentrated in vacuo. The resulting dark residue was dried under high vacuum and used in the next step without further purification (89.0 g, yield = 90 %). ¹H NMR (δ, CDCl₃): 2.13 (6H, s), 5.89 (2H, s), 7.01 (IH, d, J = 8.2 Hz), 8.09 (IH, dd, J = 8.2, 2.2 Hz), 8.79 (IH, d, J = 2.2 Hz)

References:

WO2007/113290,2007,A1 Location in patent:Page/Page column 40-41