气相SO_3磺化法合成染料中间体3-乙氨基-4-甲基苯磺酸

Synthesis of dye intermediate 3-N-ethyl-4-methylbenzenesulfonic acid by gaseous sulfur trioxide sulfonation method

以N-乙基邻甲苯胺为原料,采用气相SO3磺化法在降膜式磺化反应器中合成染料中间体3-乙氨基-4-甲基苯磺酸,用红外(IR)、电喷雾质谱(ESI-MS)和高效液相色谱(HPLC)对产物进行了表征,结果表明为目标产物.通过滴定法测定磺化产物的中和值,结果表明重复性较好.用中和值计算目标产物质量分数为93.5%,与高效液相色谱分析结果98.2%基本一致,可将中和值作为监测反应进度和产品质量的一个指标.

Dye intermediate 3-N-ethyl-4-methylbenzenesulfonic acid was synthesized by gaseous sulfur trioxide sulfonation method using N-ethyl-2-methylamiline as raw material in falling film sulfonation reactor.The product was characterized by IR,electro spray ionization-mass spectroscopy（ESI-MS） and high performance liquid dhromatography（HPLC）,and the results showed that the product was the target product.The neutralization value of sulfonated products was determined by titration method,and the results indicated good reproducibility.The content of 3-N-ethyl-4-methylbenzenesulfonic acid calculated by the neutralization value was 93.5%,which was in accordance with 98.2% determined by HPLC.Therefore,neutralization value could be used as an index monitored the reaction process and the quality of products.