Carbon Dioxide → HCID 19936656, compound

Participants

Reaction Steps

A solution of butyllithium (7.1 ml, 2.5M in hexane) is added dropwise to 5-bromo-3-[(1-methoxypiperidin-4-yl)thio]-1-methyl-1H-indole (4.5 g, prepared in Example 59) in tetrahydrofuran (45 ml) at -78° C. After 1 hour at this temperature, a stream of CO2 is passed into the solution. After the temperature has risen to 0° C., a solution of ammonium chloride is added. The reaction mixture is concentrated, taken up with ether and washed with water. The organic phase is dried over sodium sulfate and concentrated. The 3-[(1-methoxypiperidin-4-yl)thio]-1-methyl-1H-indole-5-carboxylic acid obtained (1.4 g) is crystallized from a small volume of isopropyl ether.

Provenance & Evidence