Reaction #322373

Reaction equation

tosyl chloride

5-bromoindole-3-carboxaldehyde

lithium diisopropylamide tetrahydrofuran

→

product

5-Bromo-1-(4-methyphenylsulfonyl)indole-3-carboxaldehyde

Solvents

tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   Otherevaporated
2. 2
   workup.DISSOLUTIONThe residue was dissolved in dimethylformamide
3. 3
   Filtrationfiltered
4. 4
   workup.ADDITIONthe filtrate was diluted with water
5. 5
   OtherThe precipitate was collected
6. 6
   Otherrecrystallized from ethanol

Procedure

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.

Source