Pyrogallol → 2-O-Methylpyrogallol

To a stirring solution of benzene-1,2,3-triol (2 g, 15.87 mmol) in acetone was added potassium bicarbonate (1.90 g, 19.04 mmol) and methyl iodide (3.38 g, 23.80 mmol) and the resultant reaction mixture was heated to reflux for 16 h. The reaction mixture was cooled to RT and filtered through celite bed. The filtrate was concentrated under reduced pressure, triturated with diethyl ether and the obtained solid was separated and the filtrate was concentrated under reduced pressure. Purification of the residue by flash chromatography (silica gel, 0-15% ethyl acetate in pet ether) afforded 2-Methoxybenzene-1,3-diol as a solid (600 mg, 27.2%). 4-Bromo-2-methoxybenzene-1,3-diol: To a stirring solution of 2-methoxybenzene-1,3-diol (3.0 g, 21.42 mmol) in tetrahydrofuran (30 mL) at −78° C. was added N-bromosuccinimide (4.57 g, 25.71 mmol) and the reaction mixture was stirred at −78° C. for 2 h. The reaction mixture was diluted with ice-cold water and extracted with ethyl acetate (3×). The combined ethyl acetate layers were washed with brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure. The obtained residue has mixture of products (mono and dibromo) which was used as such for further reactions (4.2 g).

1. customthe resultant reaction mixture
2. temperaturewas heated
3. temperatureto reflux for 16 h
4. filtrationfiltered through celite bed
5. concentrationThe filtrate was concentrated under reduced pressure
6. customtriturated with diethyl ether
7. customthe obtained solid was separated
8. concentrationthe filtrate was concentrated under reduced pressure
9. customPurification of the residue by flash chromatography (silica gel, 0-15% ethyl acetate in pet ether)

ORD record

ord-73443fba0ccd4050aee9f161a8910c98

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09051290B2