Study On The Selectivity Reaction Of 2,2-dichloro-1,3-benzodioxole With OH Or NH₂ And SH Group

2,2-dichloro-1,3-benzodioxole(DCBZ) is a particular reagent and can react with some compounds with active proton.In this paper,firstly,DCBZ was prepared and the molecule structure was characterized by IR and ~1H-NMR spectra.A new selective reaction was performed by the reactions of 2,2-dichloro-1,3-benzodioxole withω-Mercapto-alcohols and the mixture of alcohol and Mercapto-alcohols.By the experiment,we concluded that the OH group was prior than the SH group when was substituted by the Cl atom of DCBZ.The reactions of 2,2-dichloro-1,3-benzodioxole withω-Mercapto-alcohols were investigated.The target product of 2-Mercaptoethanol,4-Mercaptobutanol and 6-Mercaptohexanol which reacted with DCBZ was separated respectively,and was characterized by IR,GC-MS and ~1H-NMR spectra;The reaction of 3-mercaptopropanol with DCBZ was checked by GC, and the target product was identified by comparing with the authentic sample through GC, The reaction mechanism was considered as a nucleophilic reaction.Generally,the nucleophilic ability of thiol is stronger than that of alcohol in organic chemistry.But the OH group was prior to be substituted than the SH group herein.It was differred with the traditional acknowledge that the nucleophilic ability of thiol was stronger than alcohol.2-mercaptoethanol mixed with a serial of primary alcohols at the mol ratio of 1 to 1 seperately,reacted with DCBZ which was monitored by GC accordingly,then we compared the relative react-velocity of 2-mercaptoethanol with each primary alcohol selected,and concluded that 2-mercaptoethanol was easier to react with DCBZ than the selected primary alcohols,and the relative reactive activity of the selected primary alcohols was slower than 2-mercaptoethanol when they reacted with DCBZ.The mixed solution which the butylamine and the octanol were at the mol ratio of 1 to 1 reacted with DCBZ,3 hours later,and then separated the main product and characterized it by IR and ~1HNMR.then conducted the reaction of DCBZ with the mixture of the butylamine and alcohols and the reaction of DCBZ with the mixture of isopentylamine and the alcohols which the amine and alcohol were all at the mol ratio of 1 to 1,3 hours later,carried on the gas chromatography qualitative analysis.The result indicated that the primary alchohols with the increase of carbon chains and steric hindrance were slower than the amine when they reacted with DCBZ.