Once i did that type reaction,it is easy to accomplish,it is not need high temperature but need acid-binding agent.

Thanks Shi Bingyue. Could you please give me exact procedure and be more specific like acid-binding agent?

Hi,

Look at this link: http://issuu.com/thelifesciencenews/docs/chlorosulfonic_acid

There are some sugestions on benzo[b]thiopene sulphonation with chlorosulphonic acid on page 212.

Sincerely,

AD

please see

http://www.sciencedirect.com/science/article/pii/S0040402008019613

good luck

I guess you'd like to introduce the sulfonyl group at the 3 position? I would do as follow:

A solution of benzothiophene (1 eq) in sulfurochloridic acid (10 eq) is heated to 110 °C for 2h. After cooling to rt, the mixrure is poured onto xx g of ice and the aq. phase extrated with ether. The combined organic phase is washed with brine, dried over sodium sulfate, filtered and the filtrate concentrated under reduced pressure affording benzo[b]thiophene-3-sulfonyl chloride as a white solid.

To a cold [ice water/salt mixture] (~4 equivalent) chlorosulfonic acid -10C is added in small portion (1 equivalent) of your compound over a period of ~ 20 min. The ice bath is removed, and the mixture is stirred at room temperature for 4 h [follow your reaction with TLC, if starting is still there then heat in oil-bath at gradually up 80-90C for ~ hr]. Cool the solution in an ice bath again or (refrigerator) for several hours [you may need to neutralize the solution with cold NaOH solution too]. The solid is collected by filtration [if no solid material shows up then evaporate to dryness], washed with cold water- ethanol. Well I do not really know but you will find out. !

Good luck

Thank you very much Andrzej Danel, Americo Lemos, Pierre-André Fournier and Adel Amer. I will try to follow up your suggestions.

Take compound in chloroform add chlorosulphonic acid at o c. Slowly dropwise and stirred at rt.

its simple with CPBA

DCM or chloroform solvent (1mmol to 5ml solvent)

aditions (CPBA) bath ice equimolar quantities (white solid ) filter

hugs

Sulphonation is a standard reaction carried out using chlorosulphonic acid , the procedure is available in A.I.Vogel,s book.