Hydrochloric Acid → 1,3-Benzodioxol-5-ol, 4-chloro-

To a cooled (−78° C.) solution of 5-methoxymethoxy-benzo[1,3]dioxole (5.0 g, 27.35 mmol) in THF (25 mL) was slowly added 2.5 M solution of n-BuLi in hexane and stirred at nitrogen atmosphere. After 30 minutes, a solution of hexachloroethane (12.95 g, 54.7 mmol) in THF (25 mL) was added and then resulting mixture was allowed to warm to room temperature and stirred for 7 h. The reaction was diluted with water (50 mL) and extracted with ethyl acetate (2×50 mL). The organic layer was dried (Na2SO4) and concentrated under vacuum to get crude product. The obtained product was dissolved in methanol (50 mL) and 0.5 mL conc. HCl and then heated at 50° C. for 2 h. The reaction was concentrated, dissolved in ethyl acetate (50 mL) and washed with saturated aqueous sodium bicarbonate. The solvent was evaporated under vacuum to give crude product. Silica gel column chromatography (30% CH2Cl2/Hexane) gave 4-chloro-benzo[1,3]dioxol-5-ol (3c) (2.5 g, 53%). 1H NMR (CDCl3) δ 5.12 (s, 1H), 6.0 (s, 2H), 6.47 (d, 1H, J=9.0 Hz), 6.62 (d, 1H, J=9.0 Hz).

1. customresulting mixture
2. stirringstirred for 7 h
3. extractionextracted with ethyl acetate (2×50 mL)
4. dry with materialThe organic layer was dried (Na2SO4)
5. concentrationconcentrated under vacuum
6. customto get crude product
7. concentrationThe reaction was concentrated
8. dissolutiondissolved in ethyl acetate (50 mL)
9. washwashed with saturated aqueous sodium bicarbonate
10. customThe solvent was evaporated under vacuum
11. customto give crude product

ORD record

ord-693b1ca17fba4944b84c9571a145b348

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09290503B2