Acetic Acid → HCID 86588462, compound

Participants

Reaction Steps

To a solution of (6-trimethylsilanylethynyl-isoquinolin-4-yl)-acetic acid methyl ester, as prepared for Intermediate 32 (0.19 g, 0.64 mmol), in anhydrous methanol (7 ml) is added K2CO3 (72 mg) and the resulting mixture stirred for 1 h. Additional K2CO3 (11 mg) is then added and stirring continued for 30 min. The mixture is then neutralized with glacial acetic acid and concentrated. Purification by flash silica column chromatography (ethylacetate/hexane 1:1) gives (6-ethynyl-isoquinolin4-yl)-acetic acid methyl ester M+ 225. This intermediate (79 mg, 0.35 mmol) is dissolved in methanol under an inert atmosphere and 10% Pd on carbon (79 mg) added. The resulting suspension is stirred vigorously under an atmosphere of gaseous hydrogen. After 90 mins, filtration, washing with methanol and concentration give (6-ethyl-isoquinolin-4-yl)-acetic acid methyl ester MW 229. To a solution of this intermediate (68 mg, 0.30 mmol) in THF/methanol/water (3:1:1, 3.5 ml) is added LiOH (12.5 mg) and the mixture stirred for 20 h at room temperature. Concentration under reduced pressure gives lithium (6-ethyl-isoquinolin4-yl)-acetate M+ 221.

Provenance & Evidence