Boric Acid → HCID 58779044, compound

Participants

Reaction Conditions

Reaction Steps

To 1-methylindole-3-carboxylic acid (917 mg, 5.23 mmol) was added methylene chloride (20 ml). Under stirring at 0° C., oxalyl chloride (0.68 ml, 7.85 mmol) and DMF (catalytic amount) were added. After stirring at room temperature for 1.5 hours, the reaction mixture was distilled under reduced pressure to remove the solvent. The residue was added with xylene (20 ml). Methyl (4-amino-2-fluoro-3-hydroxyphenyl)acetate (1.0 g, 5.0 mmol) and boric acid (539 mg, 8.72 mmol) were added to the resulting mixture, followed by stirring at 160° C. for 3 days. After the reaction mixture was cooled to room temperature, ice water was added thereto, followed by extraction with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate, and distilled under reduced pressure to remove the solvent. The residue was subjected to chromatography on a silica gel column to collect chloroform/ethyl acetate (10/1) eluate fractions and then, purified by chromatography using a thin layer plate, whereby from chloroform/acetone (10/1) eluate fractions, methyl 7-fluoro-2-(1-methyl-3-indolyl)-6-benzoxazolylacetate (62 mg, 4%) was obtained as a pale brown solid.

Provenance & Evidence