tert-Butyl mercaptan → 3-(3-(tert-Butylthio)-1-(4-chlorobenzyl)-5-hydroxy-1H-indol-2-yl)-2,2-dimethylpropanoic acid

Participants

Reaction Steps

To a mixture of LiH (12.6 g) and HMPA (105 mL) in DMF (1050 mL) at 0° C. was added 2-methyl-2-propanethiol (178 mL). The mixture was stirred at room temperature for 30 min, then 3-[1-(4-chlorobenzyl)-3-(t-butylthio)-5-methoxyindol-2-yl]-2,2-dimethylpropanoic acid methyl ester (150 g) (EP 419,049, Example 1, Step A) in DMF (450 mL) was added slowly. The mixture was slowly heated to 150° C. and kept at that temperature for 18 hours. After cooling to room temperature, the supernatant layer was decanted and the residue dissolved in H2O and acidifed with 1N HCl, extracted twice with Et2O, washed twice with brine, dried over MgSO4, filtered and evaporated to dryness to provide the title compound.

Provenance & Evidence