2,6-二羟基-3,5-二硝基甲苯的合成新工艺

Novel Synthesis of 2,6-dihydroxy-3,5-dinitrotoluene

摘要:

2,6-二羟基-3,5-二硝基甲苯（MDNR）是合成聚对苯撑甲基苯并二噁唑（MPBO）单体的重要中间体。本文以2,6-二氯甲苯为原料经过硝化反应获得2,6-二氯-3,5-二硝基甲苯（DCDNT），纯度为99.79%、收率98.40%；再经低温CH3O-的亲核取代制得2,6-二甲氧基-3,5-二硝基甲苯（DMDNT），纯度为96.90%、收率88.36%；最后在硫酸中酸性脱甲基反应合成MDNR，纯度为99.40%，收率93.15%。MDNR的结构经过FT-IR、MS、1H-NMR 准确定性和表征。合成过程已呈现原料价廉易得，操作方便，产品质量优异，总收率80%以上，易于产业化等优点，为进一步研发合成甲基改性PBO纤维及其新单体提供关键中间体及技术来源。

Abstract:

2,6-dihydroxy-3,5-dinitrotoluene (MDNR) is one of key intermediate for poly(p-phenylene methyl benzobisoxazole) (MPBO) . In this paper, 2,6-dichloro-3,5-dinitrotoluene (DCDNT) was first prepared through the nitration of 2,6-dichlorotoluene with a purity of 99.79% and yield of 98.40%, then methoxylated with CH3O- to obtain 2,6-dimethoxy-3,5-dinitrotoluene (DMDNT) with a purity of 96.90%，and a yield of 88.36%; Finally, MDNR was successfully synthesized by the acid demethylation of DMDNT, and its purity was 99.40%，the yield was 93.15%. MDNR was identified by FT-IR, MS and 1H-NMR. This process has advantages of cheap raw materials, convenient operation, excellent product quality, the total yield of more than 80%, easy to industrialization,etc. which provides the source of key intermediate for further development of methyl modified PBO fiber.