氧气催化氧化苯氧乙醇合成苯氧乙酸

Catalytic oxidation of Phenoxyethanol to Phenoxy acetic acid with oxygen

摘要:

以苯氧乙醇和氧气为原料，经催化氧化合成苯氧乙酸。用高效液相色谱仪（HPLC）进行定量分析，红外吸收光谱（FT-IR）、核磁共振(HNMR、CNMR)、气质联用（GC-MS）对产品进行了定性分析。考察了催化剂、溶剂对反应的影响，并对反应的单因素进行了考察。结果表明：N-羟基邻苯二甲酰亚胺(NHPI）为主催化剂，丁二酮肟和乙酸钴为助催化剂，乙腈是为溶剂；固定苯氧乙醇为0.1mol， NHPI用量为苯氧乙醇摩尔量的8%，催化剂配比是n(NHPI)∶n(丁二酮肟)∶n(乙酸钴)=8∶7.5∶1，0.8 MPa氧压力，80 ℃反应6 h，在此条件下，苯氧乙酸收率达68.6%。并根据GC-MS分析结果提出了可能的反应途径。

Abstract:

Phenoxy acetic acid was prepared by catalytic oxidation reaction, using phenoxyethanol and oxygen as raw materials. HPLC(liquid chromatograph) was used for quantitative analysis, and FT-IR(Infrared absorption spectrum), NMR (nuclear magnetic resonance) and GC-MS(gas chromatography mass spectrometry) were used for qualitative analysis. Effects of Catalysts, solvents, and reaction conditions on reaction results were investigated. The results show that: N-hydroxy phthalimide(NHPI) is an efficient catalyst, and dimethylglyoxime and cobaltous acetate were suitable cocatalysts, and acetonitrile is a suitable solvent. Phenoxyethanol: 0.1mol, the amount of NHPI is 8% of molar weight of phenoxyethanol, the suitable molar ratio of NHPI: dimethylglyoxime : cobaltous acetate =8: 7.5: 1. Under the suitable reaction conditions: 80 ℃, 0.8 MPa O2 for 6h, the yield of phenoxy acetic acid was reached 68.6%. The plausible reaction pathway was proposed based on GC-MS analysis.