3-Chloro[1,2,4]triazolo[4,3-a]pyridine synthesis

Yield:4922-74-1 75%

Reaction Conditions:

with pyrylium tetrafluoroborate;magnesium chloride in acetonitrile; for 16 h;Heating;Sealed tube;

Steps:

General procedure for the chlorination of amino heteroaromatic compounds

General procedure: Unless otherwise specified, an 18 ml screw-capped tube under normal atmosphere is charged with pyrylium tetrafluoroborate 1 (1.5 equiv.) and MgCl₂ (2.0 equiv.). The starting material (1.0 equiv.) is then added and directly followed by CH₃CN (0.1 M). The resulting mixture is then stirred 5 minutes at 25 °C and then 16 hours at 120 °C. The reaction is allowed to cool to 25 °C. The crude mixture is partitioned between water and EtOAc. The aqueous layer is extracted with EtOAc (3 × 10 ml). The combined organic layers are dried over Na₂SO₄, concentrated to dryness and purified on silica gel to afford the desired product.

References:

Ghiazza, Clément;Faber, Teresa;Gómez-Palomino, Alejandro;Cornella, Josep [Nature Chemistry,2022,vol. 14,# 1,p. 78 - 84]