RING-OPENING POLYMERIZATION OF l,4-DIOXAN-2-ONE INITIATED BY LANTHANUM TRIS(2,6-DI-TERT-BUTYL-4-METHYLPHENOLATE)

The ring-opening polymerization of 1,4-dioxan-2-one （PDO） was carried out by lanthanum tris（2,6-di-tert-butyl-4- methylphenolate） （La（OAr）3） as novel single component initiaLor. The influences of polymerization reaction temperature and the molar ratio of monomer to initiator on the monomer conversion and molecular weight of poly（1,4-dioxan-2-one） （PPDO） were explored. PPDO with high viscosity average molecular weight of 1.95×10^5 can be prepared at 40℃ when [PDO]/ [La（OAr）3] molar ratio was 800. Mechanism investigation shows that the polymerization proceeds through a ＂coordination- insertion＂ mechanism with selective rupture of acyl-oxygen be,nd of PDO.

Polymerization of n-Hexyl Isocyanate Initiated by Novel Rare Earth Tris(2,6-di-tert-butyl-4-methylphenolate)

The polymerization of n-hexyl isocyanate(HNCO) was carried out in the presence of a novel single initiator, rare earth tris(2,6-di-tert-butyl-4-methylphenolate)[Ln(OAr)_3]. The influences of reaction conditions such as the monomer concentration, the polymerization temperature and time, and the types of solvents on the polymerization of HNCO were studied. Polymerizations of phenyl, i-propyl, p-tolyl, n-butyl and n-octyl isocyanates with La(OAr)_3 were also examined.

Visible-light-induced novel cyclization of 2-(2-(arylethynyl)benzylidene)-malononitrile derivatives with 2,6-di(tert-butyl)-4-methylphenol to bridged spirocyclic compounds

A green and highly efficient strategy for the preparation of bridged spirocyclic compounds via visible-light-induced cyclization of 2-(2-(arylethynyl)benzylidene)malononitrile derivatives with 2,6-di(tert-butyl)-4-methylphenol(BHT)at room temperature was developed.The photoinduced radical reactions generated the corresponding products in good yields under simple and mild reaction conditions.

卡巴拉汀透皮贴片中2,6-二叔丁基-4-甲基苯酚的HPLC法测定

建立了高效液相色谱法测定卡巴拉汀透皮贴片中的抗氧剂2,6-二叔丁基-4-甲基苯酚（BHT）。采用冰水浴超声提取卡巴拉汀透皮贴片中的BHT,采用Inert Sustain C18色谱柱,流动相为甲醇∶20 mmol/L乙酸铵缓冲溶液（80∶20）,检测波长278 nm。BHT在2.25~13.50μg/ml范围内线性关系良好,定量限为90 ng/ml。平均回收率为100.9%,RSD为3.17%。

注射用埃索美拉唑钠中2,6-二叔丁基-4-甲基苯酚和4-叔丁基酚迁移量的UPLC法测定

建立了超高效液相色谱法测定注射用埃索美拉唑钠中的2,6-二叔丁基-4-甲基苯酚(BHT)和4-叔丁基酚。采用二氯甲烷提取4-叔丁基酚和BHT,使用Eclipse plus C18柱,流动相为水和甲醇,线性梯度洗脱,检测波长280 nm。结果表明,BHT和4-叔丁基酚在0.4~10.0μg/ml范围内线性关系良好,回收率为81%~117%,RSD为0.4%~6.6%。本方法简捷、可靠,可为不同制剂中BHT和4-叔丁基酚的迁移量测定提供参考。

四(五氟化苯基)-六,七溴-卟啉氯化铁选择性催化氧化超临界丙烷的反应机理

以2,6-二叔丁基-4-甲基苯酚(BHT)为自由基捕捉剂,研究了四(五氟化苯基)-六,七溴-卟啉氯化铁选择性催化氧化超临界丙烷为丙醇的反应机理.结果表明,添加少量的BHT能促进反应进行,过量的BHT则抑制反应进行.反应产物中除有丙基自由基外,还有异丙氧自由基及其他微量反应产物(如异己烷、正己烷、双丙基过氧化物)存在.超临界丙烷在催化剂的作用下形成更多的丙基自由基,进一步证明金属卟啉催化氧化超临界丙烷是链式自由基自氧化反应机理.对于其他微量反应产物如乙醇、乙酸和丙酸的存在,不能用链式自由基自氧化反应机理进行解释.

色谱分析501抗氧防胶剂纯度及游离甲酚含量

采用毛细管气相色谱技术 ,使用二甲基聚硅氧烷毛细管色谱柱 ,利用程序升温、程序升压及分流进样法 ,通过实验选择最佳分析操作条件 ,较成功地测定出 5 0 1抗氧防胶剂纯度及其游离甲酚含量。