Reaction #479217

Reaction equation

N-ethyl-benzo[b]thiophene-3-sulphonamide

trioxane

→

4-ethyl-4,5-dihydro-1,3-dithia-4-aza-acenaphthylene 3,3-dioxide

Solvents

methanesulphonic acid

trifluoroacetic acid

Conditions

Workup

1. 1
   OtherThe solid formed
2. 2
   Otheris separated off by filtration
3. 3
   Washwashed with 200 ml of water
4. 4
   workup.DISSOLUTIONdissolved while hot in 400 ml of ethanol/isopropanol (1:1)
5. 5
   Otherseparated from solid residues
6. 6
   Filtrationby filtering again
7. 7
   Otheris purified by chromatography

Procedure

1.90 g of N-ethyl-benzo[b]thiophene-3-sulphonamide are dissolved in 25 ml methanesulphonic acid at 35° C. and combined with a solution of 0.29 g of trioxane in 8 ml of trifluoroacetic acid. After 2.5 h stirring at ambient temperature the reaction mixture is poured onto 400 ml of ice water. The solid formed is separated off by filtration, washed with 200 ml of water and then dissolved while hot in 400 ml of ethanol/isopropanol (1:1) and separated from solid residues by filtering again. The residue remaining after the concentration of the filtrate is purified by chromatography. Yield: 0.82 g. M.p.: 156° C.

Source