Bromide ion → 5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-1-bromo-2-methoxymethoxynaphthalene-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-bromo-3-hydroxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl acid (Compound M), 233 mg, 0.71 mmol) in 6 ml of CH2Cl2 was added chloromethyl methyl ether (0.162 ml, 2.1 mmol), diisopropylethyl amine (0.764 ml, 4.2 mmol) and a catalytic amount of tetrabutylammouimn bromide. The reaction mixture was heated to 45° C. for 2 h. The reaction mixture was concentrated and the residue was purified by column chromatography (ethyl acetate/hexane 1/9) to yield the methoxymethyl ester of the title compound as a white solid (200 mg). This white solid was further dissolved in 20 ml of EtOH. An aqueous solution of NaOH (0.5 ml, 1M) was added. The reaction mixture was stirred at room temperature for over night. The EtOH was removed and the residue was added 2 ml of ethyl acetate and 3 ml of water. This mixture was very slowly acidified with 10% HCl to PH=7. The ethyl acetate layer was separated and washed with brine, dried over Na2SO4. After filtration of the drying agent and removal of solvent, the reaction yielded the title compound as a white solid (155 mg). 1H NMR d 7.99 (s, 1H), 5.20 (s, 2H), 3.66 (s, 3H), 1.74 (m, 2H), 1.67 (m, 2H), 1.60 (s, 6H), 1.32 (s, 6H).

Provenance & Evidence