Water → 7-(Hydroxymethyl)-4-(2-methyl-1,3-thiazol-4-yl)-2H-chromen-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-(2-methyl-1,3-thiazol-4-yl)-2-oxo-2H-chromene-7-carboxylic acid (250 mg, 0.87 mmol) in THF (10 mL) triethylamine (0.31 mL, 2.18 mmol) was added. The mixture was stirred until it became a clear solution. The reaction was then cooled to 0° C. and isobutylchloroformate was added dropwise (230 uL, 1.74 mmol). After 1 hour stirring at 0° C. a solution of sodium borohydride in water (132 mg, 3.48 mmol in 3.5 mL) was added slowly and the mixture was stirred for another hour. The reaction mixture was quenched with a saturated ammonium chloride solution and the product was extracted with ethyl acetate. The combined organic extracts were washed with water and brine, dried over MgSO4, filtered and concentrated under reduced pressure. The crude residue obtained was used as such for the next step. 1H NMR (400 MHz, acetone-d6): 8.26 (d, 1H), 8.07 (s, 1H), 7.42 (s, 1H), 7.35 (d, 1H), 6.64 (s, 1H), 4.80 (d, 2H), 4.56 (t, 1H), 2.85 (s, 3H).

Provenance & Evidence