PBO关键中间体4-氨基-6-硝基间苯二酚盐酸盐的合成

Synthesis of 4-amino-6-nitroresorcinol hydrochloride,a key intermediate for PBO

系统地研究了PBO关键中间体4-氨基-6-硝基间苯二酚盐酸盐(ANR.HCl)的合成新工艺及其优化条件,在初步探索实验的基础上,选用混合正交表L18(2×37)及5个影响因子,进行4,6-二硝基间苯二酚(DNR)选择还原、成盐合成ANR.HCl的正交优化实验,并进行二次调优实验。结果表明:在95%高置信度时活性炭用量影响显著,在对其进行再次单独调优实验后,合成出收率90.73%、HPLC纯度94.05%的ANR.HCl产品,相应优化条件为:10.0gDNR以150mL乙醇为溶剂,在1.5gC/1.0gFeSO4.7H2O催化下用6.62g85%水合肼回流还原反应1h。精制后产品经FT-IR、1HNMR、13CNMR及MS等定性确认,具有产品的稳定性好、还原过程选择性高,污染低及操作方便等特点。

Novel synthesis and optimal reaction conditions for 4-amino-6-nitroresorcinol hydrochloride （ANR.HCl）,a key intermidiate of poly（p-phenylene-2,6-benzobisoxazole）（PBO）,were systematically studied. Effect of solvent dosage,activated carbon and FeSO4.7H2O,molar ratio of hydrazine hydrate and reaction time were optimizied with an L18（2×37）orthogonal test and a 2nd step optimization. ANR.HCl was obtained with 90.7% yield and 94.1% purity by selective reduction of 4,6-dinitroresorcino（lDNR）under the optimized conditions of 10.0g of DNR,1.5 g activated carbon,1.0g of FeSO4.7H2O,6.62 g of 85% hydrazine hydrate and reflux for 1 h in 150 mL ethanol. The refined ANR.HCl was identified by FT-IR,1H NMR,13C NMR and MS. The current process has the advantages of excellent product stability,high-selectivity,less organic pollution,easy operation and so on.