Hydrochloric Acid → Ethyl 3-(3-(tert-butylthio)-1-(4-chlorobenzyl)-5-hydroxy-1H-indol-2-yl)-2,2-dimethylpropanoate

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Reaction Conditions

Reaction Steps

Aluminum chloride (4.1 g; 30.7 mmol) was suspended in 9 mL t-butylthiol and cooled to 0° C. Ethyl 3-[1-(4-chlorobenzyl)-3-(1,1-dimethylethylthio)-5-methoxyindol-2-yl]-2,2-dimethylpropionate (5.0 g; 10.2 mmol), prepared as in step 3, in 12 mL dichloromethane was added and the reaction mixture was stirred at 0° C. for 10 min and then at ambient temperature for 3 hours. The reaction mixture was poured into ice and acidified with 10% aqueous HCl. The mixture was extracted three times with dichloromethane. The combined extracts were rinsed with brine, dried over magnesium sulfate and concentrated. The dark brown residue was filtered through silica gel eluting with 10% diethyl ether in dichloromethane. Evaporation of the solvent afforded ethyl 3-[1-(4-chlorobenzyl)-3-(1,1-dimethylethylthio)-5-hydroxyindol-2-yl]-2,2-dimethylpropionate. m.p. 151°-152° C. 1H NMR (300 MHz, DMSO-d6) δ1.10 (t, J=7 Hz, 3H), 1.12 (s, 6H), 1.20 (s, 9H), 3.19 (bs, 2H), 4.04 (q, J=7 Hz, 2H), 5.41 (s, 2H), 6.58 (dd, J=9, 3 Hz, 1H), 6.83 (d, J=9 Hz, 2H), 6.98 (d, J=3 Hz, 1H), 7.13 (d, J=9 Hz, 1H), 7.32 (d, J=9 Hz, 2H), 8.88 (s, 1H). MS (DCI/NH3) 474 (M+H)+.

Provenance & Evidence