Phosphorus oxychloride → 5-(2-Chloro-4-pyridyl)-2-ethyl-4-(3-methylphenyl)-1,3-thiazole

Reaction equation

[CH2:1]([C:3]1[S:4][C:5]([C:15]2[CH:20]=[CH:19][N+:18]([O-])=[CH:17][CH:16]=2)=[C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([CH3:14])[CH:9]=2)[N:7]=1)[CH3:2].C(=O)([O-])O.[Na+].P(Cl)(Cl)([Cl:29])=O>>[Cl:29][C:19]1[CH:20]=[C:15]([C:5]2[S:4][C:3]([CH2:1][CH3:2])=[N:7][C:6]=2[C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([CH3:14])[CH:9]=2)[CH:16]=[CH:17][N:18]=1

Participants

Reactant 3

HCID 24813Phosphorus oxychloride

HCID 516892Sodium Bicarbonate

HCID 113239374-[2-Ethyl-4-(3-methylphenyl)-1,3-thiazol-5-YL]pyridine N-oxide

Product 1

HCID 116740635-(2-Chloro-4-pyridyl)-2-ethyl-4-(3-methylphenyl)-1,3-thiazoleYield 81%

Procedure

A solution of 4-[2-ethyl-4-(3-methylphenyl)-1,3-thiazol-5-yl]pyridine N-oxide (1.00 g, 3.37 mmol) in phosphorus oxychloride (6.5 mL) was stirred at 100° C. for 2 hours. The reaction solution was cooled, and poured into a saturated aqueous sodium hydrogen carbonate solution, and extracted with ethyl acetate. The extracts were washed with brine, then, dried, and concentrated. The residue was purified by silica gel column chromatography (hexane-ethyl acetate=2:1) to obtain a title compound (0.90 g, yield 81%).