6-bromo-1-fluoronaphthalen-2-ol synthesis

Yield:442150-49-4 88%

Reaction Conditions:

Stage #1: 6-bromo-naphthalen-2-olwith Selectfluor in acetonitrile at 20; for 2 h;
Stage #2: with sodium dithionite in water;isopropyl alcohol;toluene at 20; for 24 h;Inert atmosphere;

Steps:

General procedure A

General procedure: To a solution of substituted naphthalen-2-ol (10 mmol) in MeCN (100 mL) was added the 1-Chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (20 mmol) in roomtemperature. The resulting mixture was stirred for 2 h and then added the water, the organic layer wasseparated and the aqueous layer was extracted with ethyl acetate, and the combined organic layer was driedover anhydrous MgSO4 and concentrated under reduced pressure. The crude product was directly used inthe next step without purification.To a round-bottom flask was added the Na2S2O4 (25 mmol) in iPrOH (50 mL) and H2O (50 mL) atroom temperature under argon. Then the above obtained crude product in toluene (100 mL) at roomtemperature under argon was added to the round-bottom flask dropwise. The resulting mixture was stirredfor 24 h under argon and then added the water, the organic layer was separated and the aqueous layer wasS3extracted with ethyl acetate, and the combined organic layer was dried over anhydrous MgSO4 andconcentrated under reduced pressure. The residue was then chromatographed on silica gel to afford thesubstituted 1-fluoronaphthalen-2-ol as a solid.

References:

Zhang, Naichen;Ye, Yuanzhi;Bai, Lu;Liu, Jingjing;Wang, Han;Luan, Xinjun [Chinese Chemical Letters,2022,vol. 33,# 5,p. 2411 - 2414] Location in patent:supporting information