Lithium Hydroxide → 5-(Propan-2-yloxy)pyridine-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To methyl 5-hydroxypyridine-2-carboxylate (0.6 g, 3.92 mmol) in DMF (3.6 mL) was added potassium carbonate (2.2 g, 15.7 mmol) followed by 2-bromopropane (736 μL, 7.8 mmol) The reaction mixture was heated at 60° C. for 1.5 hours. The reaction mixture was cooled and filtered using EtOAc and the solvent was evaporated under reduced pressure. The residue was dissolved in EtOAc and washed with water (3×10 mL) and brine solution (10 mL). The organics were separated and dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography using 0-50% EtOAc: hexanes as eluent to give methyl 5-isopropoxypyridine-2-carboxylate (555 mg, 73%) as a colorless oil. ESI-MS m/z calc. 195.1. Found 196.3 (M+1)+; Retention time: 1.09 minutes (3 min run). Lithium hydroxide (5.7 mL of 2 M, 11.37 mmol) was added to a solution of methyl 5-isopropoxypyridine-2-carboxylate (555 mg, 2.84 mmol) in dioxane (4 mL) and stirred at 55° C. for 2 hours. The reaction mixture was diluted with ethyl acetate and washed with water and layers were separated. The aqueous layer was acidified with 1N HCl solution and extracted with ethyl acetate. The organics were separated and dried over sodium sulfate, filtered and concentrated in vacuo to give 5-isopropoxypyridine-2-carboxylic acid (150 mg, 29%). ESI-MS m/z calc. 182.1. Found 182.3 (M+1)+; Retention time: 0.33 minutes (3 min run).

Provenance & Evidence