4-Toluenesulfonyl chloride → 5-bromo-1-(4-methylbenzenesulfonyl)-1H-indole-3-carbaldehyde

Participants

Reaction Steps

To a solution of 5-bromoindole-3-carboxaldehyde (10 g) in dry tetrahydrofuran (75 ml), cooled to −78° C., was added with 2M lithium diisopropylamide/tetrahydrofuran (22.5 ml). After 30 min., the mixture was treated with a solution of tosyl chloride (9.5 g) in dry tetrahydrofuran (75 ml). The mixture was allowed to warm to room temperature overnight and evaporated. The residue was dissolved in dimethylformamide, filtered, and the filtrate was diluted with water. The precipitate was collected and recrystallized from ethanol to give 42 g (25%) of product.

Provenance & Evidence