Reaction #51663

Reaction equation

1-methylsulfanyl-propan-2-one

2-chloroaniline

triethylamine

t-butyl hypochlorite

→

7-Chloro-2-methyl-3-methylsulfanyl-1H-indole

Solvents

dichloromethane

dichloromethane

dichloromethane

dichloromethane

Water

Conditions

Workup

1. 1
   workup.ADDITIONwas added
2. 2
   workup.ADDITIONwas added
3. 3
   workup.ADDITIONUpon completion of the addition
4. 4
   Otherto reach ambient temperature
5. 5
   Otherthe layers were separated
6. 6
   Dryingthe organic layer was dried over magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   Otherthe solvent evaporated to dryness
9. 9
   OtherThe residue was purified by column chromatography on silica gel using
10. 10
    workup.ADDITIONa mixture of hexane-ethyl acetate (95:5)
11. 11
    Washto elute 7-chloro-2-methyl-3-methylsulfanyl-1H-indole (1.94 g) as an oil

Procedure

Using the procedure described in J. Amer. Chem. Soc., 1974, 96 (17) 5495 , 2-chloroaniline (1.27 g, 10 mmole) was dissolved in dichloromethane (35 ml) and cooled to −65° C. To this solution was added dropwise with vigorous stirring, t-butyl hypochlorite (1.08 g, 10 mmole) in dichloromethane (5 ml). After 10 minutes 1-methylsulfanyl-propan-2-one (1.04 g, 10 mmole) dissolved in dichloromethane (5 ml) was added. The mixture was stirred at −65° C. for 1 h more. At this point triethylamine (1.01 g, 10 mmole) dissolved in dichloromethane (5 ml) was added. Upon completion of the addition, the reaction mixture was allowed to reach ambient temperature. Water was added and the layers were separated, the organic layer was dried over magnesium sulfate, filtered and the solvent evaporated to dryness. The residue was purified by column chromatography on silica gel using a mixture of hexane-ethyl acetate (95:5) to elute 7-chloro-2-methyl-3-methylsulfanyl-1H-indole (1.94 g) as an oil.

Source