3,3′-二氯联苯胺盐酸盐合成新工艺的研究

<title>Study on New Technology ofSynthesis of 3,3′Dichlorobenzidine

以邻硝基氯苯(A)为原料,经过3步化学反应合成3,3′-二氯联苯胺盐酸盐(D):(A)在0.2g1,4-萘醌催化下与CH2O/NaOH(摩尔比为n(NaOH)/n(CH2O)=0.85∶1)在56～57℃反应7h,得到2,2′-二氯氧化偶氮苯(B),产率91.0%;(B)在0.5gAl-Ni合金及0.3g1,4-萘醌催化下与水合肼在56～57℃反应7.5h,得到2,2′-二氯氢化偶氮苯(C),产率97.0%;(C)在盐酸中分别于5℃反应2h、于10℃反应11h、于23～24℃反应11h得到(D)。(D)的总产率达到85.5%,纯度(质量分数)97.7%。

<Abstrcat>3,3′Dichlorobenzidine(D) was synthesized from onitrochlorobenzene(A) by three chemical reaction steps. 2,2′dichloroazoxybenzene(B) was obtained in 91.0% yield through (A) reacted with CH2O/NaOH (mole ratio: n(NaOH)/n(CH2O)=0.85∶1) in the presence of 1,4naphthoqinone(0.2g) at 56～57℃ for 7h, 2,2′dichlorohydrazobenzene(C) was gained in 97.0% yield through (B) reacted with N2H4·H2O in the presence of AlNi alloy (0.5g) and 1,4naphthoqinone(0.3 g) at 56～57℃ for 7.5 h, and (D) was got through (C) reacted with HCl/H2O at 5℃ for 2h, 10℃ for 11h and 23～24℃ for 11 h, respectively.The total yield and the purity of(D) can reached to 85.5% and 97.7%, respectively.