Sodium Hydroxide → 5-Chloro-7-methyl-1-benzofuran

A solution of [(4-chloro-2-formyl-6-methylphenyl)oxy]acetic acid (4.69 mmol) in acetic anhydride (20 mL) was treated with sodium acetate (14.07 mmol). The resulting solution was heated to reflux and stirred for three days. The brown reaction solution was allowed to cool to room temperature, and was diluted with toluene (10 mL). The solution was then treated with 1N aq NaOH (10 mL) and was stirred at room temperature for 20 min. The solution was then further diluted with water (50 mL) and was extracted using ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered, and concentrated in vacuo. The resulting brown residue was purified by flash chromatography (hexanes) to provide the title compound as a clear oil (120 mg, 15% yield). 1H NMR (400 MHz, DMSO-d6) ppm 8.07 (d, J=2.27 Hz, 1H) 7.55 (d, J=1.77 Hz, 1H) 7.20 (d, J=1.01 Hz, 1H) 6.94 (d, J=2.27 Hz, 1H) 2.47 (s, 3H).

1. temperatureThe resulting solution was heated
2. temperatureto reflux
3. stirringwas stirred at room temperature for 20 min
4. extractionwas extracted
5. dry with materialThe combined organic layers were dried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe resulting brown residue was purified by flash chromatography (hexanes)

ORD record

ord-304dc9b9e5ea4cbb80c61bf52bb7240f

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09340529B2