2,2,6,6-Tetramethylpiperidine is a hindered amine light stabilizer that is low in toxicity and highly efficient. It contains reactive groups that can be bonded to polymer chains, resulting in improved performance. It does not easily volatilize during processing and does not affect the original color of the material. It is compatible with most industrial solvents and significantly enhances the light and oxidative aging resistance of polyethylene plastics, fiber products, and polypropylene materials, surpassing conventional UV absorbers and quenchers [1]. Synthesis Figure 1: Synthesis route of 2,2,6,6-tetramethylpiperidine [2]. The HPLC pump and receiver with a cold trap are connected to a microreactor. The reactor is heated in a nitrogen flow (50 ml/min) in an oven to 250°C. Once this temperature is reached, an incremental amount of hydrogen is mixed into the N2 flow until the proportion of hydrogen is 100%. The temperature is then raised for 30 minutes to 350°C and subsequently lowered to 100°C. At this temperature, THTMP of Example A1 is added at a rate of 4.2 ml/h using the pump. Hydrogen is simultaneously added at a rate of 50 ml/min. The reaction is quantitatively completed at 110-130°C. The total yield of 2,2,6,6-tetramethylpiperidine obtained in the form of a colorless liquid is actually 100%. 2,2,6,6-Tetramethylpiperidine, yield 100%. The synthesis route is shown in Figure 1. Figure 2: Synthesis route of 2,2,6,6-tetramethylpiperidine. Hydrazine hydrate (1.0 L, 1.0 kg, 21 mol) is added to liquid triacetone amine (mp 34-38°C; 2.0 kg, 13 mol) within 30 minutes. Due to moderate exothermic reaction, the temperature temporarily rises to 90°C. The viscous but uniform brown mixture is kept at 60°C in a bath and potassium hydroxide (48 g, 0.85 mol) in a solution of diglycol (0.25 L) and paraffin oil (60 mL) is carefully dripped into it at a rate of 2.5 g/min using a pump (model ProMinent Electronic A2001). The solution is maintained at 210°C (±10°C) in a polyethylene glycol bath (see Figure 1). The formed 2,2,6,6-tetramethylpiperidine and released H2O are continuously removed through a 50 cm Vigreux column by distillation and collected in a separation funnel until the reaction is terminated. The organic layer obtained by distillation yields 2,2,6,6-tetramethylpiperidine. It is a colorless liquid with a yield of 1.51 kg (83%). bp 155-157°C; nD20 1.4454 [raised to nD20 1.4555]; d420 is 0.837. The synthesis route is shown in Figure 2. Figure 3: Synthesis route of 2,2,6,6-tetramethylpiperidine. 2,2,6,6-Tetramethyl-4-oxapiperidine-1-oxyl (10 mmol), excess ethanethiol (approximately 5 ml/1 g nitroxide), and benzene (approximately 2.5 ml/1 ml ethanethiol) are mixed. After completion of the reaction (solution turns colorless), the mixture is extracted with 1 M hydrochloric acid. The acidic layer is carefully alkalized with potassium carbonate. The acidic layer is extracted with dichloromethane. The organic layer is dried with magnesium sulfate. The organic layer is filtered. The organic layer is evaporated. The purified product (distillation, crystallization, sublimation, or chromatography) yields the titled compound 2,2,6,6-tetramethylpiperidine. References [1] Cai, Z., Ding, L. (2021). Synthesis method of 2,2,6,6-tetramethylpiperidine. Plastic Additives, (02), 36-37+58. [2] Zakrzewski, J. (1990). A reaction of nitroxides with ethyl mercaptan. A mild method for the conversion of nitroxides into their corresponding amines. Monatshefte fuer Chemie, 121(10), 803-8. ...

甲基胡椒基环氧丙酸乙酯是一种常温常压下的白色固体。它是一种有机合成和医药领域常用的中间体，可用于合成药物分子和生物活性分子。通过其环氧结构，可以制备各种甲基胡椒基衍生物。 图1 甲基胡椒基环氧丙酸乙酯的性状图 甲基胡椒基环氧丙酸乙酯的合成方法 图2 甲基胡椒基环氧丙酸乙酯的合成路线 在干燥的反应烧瓶中，将甲基胡椒基环氧丙酸乙酯的苯乙烯前体化合物（2 mmol）溶于二氯甲烷（20 mL）中，然后将反应溶液冷却至0℃。缓慢加入间氯过氧苯甲酸（863 mg，5 mmol），在室温下搅拌反应15小时。反应结束后，用二氯甲烷萃取混合物三次，洗涤有机层，干燥后浓缩得到目标产物。 甲基胡椒基环氧丙酸乙酯的应用 甲基胡椒基环氧丙酸乙酯可用作有机合成和医药领域的中间体。通过与有机胺反应，可以得到开环胺化的产物。 图3 甲基胡椒基环氧丙酸乙酯的应用 在干燥的反应器中，将甲基胡椒基环氧丙酸乙酯溶于甲醇中，加入甲基胺的四氢呋喃溶液，回流搅拌反应。反应结束后，中和反应体系，用乙酸乙酯萃取混合物，干燥后浓缩得到目标产物。 参考文献 [1] Lee, Ji Hyun et al Forensic Science International, 313, 110332; 2020 ...

正己胺 是一种在制药领域中具有重要药用价值的化合物。它在制药中被广泛应用于治疗多种疾病，具有抗菌、抗炎和镇痛等多种药理作用，使其成为许多药物的重要成分之一。正己胺可以用于制备抗生素、抗病毒药物、止痛药和抗癌药等多种药品。 在使用正己胺时，剂量的确定非常重要。医生会根据患者的年龄、体重、症状等因素来决定合适的剂量，并根据需要进行调整。正确的剂量可以确保药物在患者体内发挥最佳的疗效，同时避免不必要的副作用。 在制药过程中，确保正己胺的质量和纯度也是至关重要的。制药公司需要选择可靠的供应商，并遵循相关的质量控制标准，以确保生产出符合要求的正己胺制剂。 综上所述，正己胺在制药中具有重要的药用价值。它作为多种药物的重要成分，具有抗菌、抗炎和镇痛等多种药理作用。在使用正己胺时，剂量的准确确定非常重要，需要根据患者情况和医生建议进行调整。制药公司在使用正己胺时应注重质量控制，确保药物的质量和疗效符合标准。 ...

试过了，氧化炉烧到500°排胶不会变黑 ... 如果排胶不会发给，说明是胶没有排干净导致石墨炉里面烧结胶中的c排不干净而被包裹在陶瓷里面发黑。500度空气气氛下排聊对陶瓷性能影响不是很大。 ...

醛形成的亚胺一般用三乙酰氧基硼氢化钠还原即可，氢化控制不好有时候只还原醛成醇了而没能实现还原胺化。

时间长了容易导致过载

1. 成像前用清水漂洗琼脂糖胶；2. 成像设备 调整，比如减小ISO，提高信噪比。

张化机不是天沃吗？

我用的是HPMC

破案了，因为玻璃太脏了

有联系电话吗？

你的文章几个审稿人？这样一般不会拒

如果jacs级别的占了百分之四十，觉得可以啊，弄个岗位。如果是ACB JMCA那难整

是要氘代C-H，N-H还是全部？这两个方法完全不同

另外， 欢迎引用下面的 这篇综述：A review of carbon-composited bifunctional electrocatalysts as air-electrode materials for metal-air batteries, Electrochem. Energy Rev. 2018, 1, 1-34。 顺便说一下：El ... ECER确实不错，我也是刚中了一篇。哈哈。 ...

一起工作养家，一起分担家务。谁累了另一方体谅下多做点，没有硬性分工。

人家知道咱们中国人爱发文章，需求量贼大

也许要用到旋转圆盘环盘电极装置

密封分为低压密封和高压密封，低温阀门有逸散性试验、深冷泄露试验等，

酸敏感，不能用强酸。也可能是工艺处理的问题