THE BASE PRESENCE AT THE ALKYLSULFOCHLORINATION OF β-AMINOPROPIOAMIDOXIMES IN CHLOROFORM AND WATER

Abstract

We have studied the regioselectivity of alkylsulfochlorination of β-(4-phenylpiperazin-1-yl)- and β-(benzimidazol-1-yl)-propioamidoximes using AlkSO2Cl under two conditions: (i) in chloroform in the presence of tributylamine (Bu3N) as a base at room temperature (r.t.); (ii) in water and acetone (4:1) without Bu3N at r.t. The reaction under the conditions (i) leads to the return of the original amidoximes, the formation of 2-amino-8-phenyl-1,5,8-triazaspiro[4.5]dec-1-ene-5-ammonium chloride and β-(benzimidazole-1-yl)propioamidoxime hydrochloride. When alkylsulfochlorination occurs under conditions (ii): β-(4-phenylpiperazin-1-yl)propioamidoxime reacts with iso-propylsulfonyl chloride and β-(benzimidazol-1-yl)propioamidoxime ‒ with methylsulfonyl chloride, 2-amino-8-phenyl-1,5,8-triazaspiro[4.5]dec-1-ene-5-ammonium hydrochloride, iso-propylsulfonate and O-methylsulfonyl-β-(benzimidazol-1-yl)propioamidoxime hydrochloride were obtained in quantitative yields. Thus, under conditions (i) Bu3N binds alkylsulfochlorides into alkylsulfonyltributylammonium chlorides and the alkylsulfochlorination products of β-aminopropioamidoximes were not formed; under conditions (ii) alkylsulfochlorination products were isolated: 2-amino-8-phenyl-1,5,8-triazaspiro[4.5]dec-1-ene-5-ammonium iso- hydrochloride, propylsulfonate and O-methylsulfonyl-β-(benzimidazole-1-yl)propioamidoxime hydrochloride.