合成2-(三溴甲磺酰基)吡啶的工艺改进

Process Improvment on the Synthesis of 2-Pyridyl Tribromomethyl Sulfone

聚乙二醇-400催化2-氯吡啶(1)与甲硫醇钠反应合成了2-甲硫基吡啶(2);2与次溴酸钠经氧化和溴化反应合成了2-三溴甲磺酰吡啶(3),其结构经1H NMR,IR和元素分析确证。合成2的最佳反应条件为:1 100mmol,甲硫醇钠0.12 mol,聚乙二醇-400(1.2 mL)为催化剂,于80℃反应4 h,收率98%。合成3的最佳反应条件为:2 95 mmol,n(2)∶n(溴素)=1.00∶6.58,于8℃反应5 h,收率95.1%,纯度99.6%。

2-Methylthiopyridine（ 2） was obtained by reaction of 2-chloropyridine and sodium methylmercaptide using polyethylene glycol 400 as the phase transfer catalyst. 2-Pyridyl tribromomethyl sulfone（ 3） was synthesized by oxdation and bromination reaction of 2. The structures were confirmed by 1H NMR,IR and elemental analysis. The optimum reaction conditions at 80 ℃ for 4 h of synthesizing 2 were as followes： 1 was 100 mmol,sodium methylmercaptide was 0. 12 mol,and PEG-400（ 1. 2 mL） was the catalyst,the yield was 98%. The optimum reaction conditions at 8 ℃ for 5 h of synthesizing 3 were as followes： 2 was 95 mmol,n（ 2） ∶ n（ bromine） = 1. 00 ∶ 6. 58,the yield was 99. 6% and the purity was 95. 1%.