71999-74-1Relevant articles and documents
Toward Enantiomerically Pure β-Seleno-α-amino Acids via Stereoselective Se-Michael Additions to Chiral Dehydroalanines
Oroz, Paula,Navo, Claudio D.,Avenoza, Alberto,Busto, Jesús H.,Corzana, Francisco,Jiménez-Osés, Gonzalo,Peregrina, Jesús M.
supporting information, p. 1955 - 1959 (2021/01/13)
The first totally chemo- and diastereoselective 1,4-conjugate additions of Se-nucleophiles to a chiral bicyclic dehydroalanine (Dha) are described. The methodology is simple and does not require any catalyst, providing exceptional yields at room temperature, and involves the treatment of the corresponding diselenide compound with NaBH4 in the presence of the Dha. These Se-Michael additions provide an excellent channel for the synthesis of enantiomerically pure selenocysteine (Sec) derivatives, which pose high potential for chemical biology applications.
Method for synthesizing lorcaserin intermediate p-chlorophenethylamine
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Page/Page column 0031; 0033; 0049; 0051, (2019/09/13)
The invention discloses a method for synthesizing a lorcaserin intermediate, namely p-chlorophenethylamine. The method is characterized in that p-chlorophenethylamine is prepared from p-halogen chlorobenzene and halogenated ethylamine under the action of a catalyst, and the reaction process comprises the following steps: 1) uniformly mixing halogenated ethylamine, a protecting agent, an alkali 1 and a solvent S1, stirring at 50-70 DEG C to perform a reaction for 6-8h, and filtering off solids so as to obtain a mixture M1; 2) under the protection of a protection gas, uniformly mixing p-halogenchlorobenzene, copper iodide, a solid alkali and a solvent S2, controlling a reaction temperature to 130-145 DEG C and reaction pressure to 3-5atm, stirring for 50-70min, dropping the mixture M1, controlling the reaction temperature to 150-170 DEG C and the reaction pressure to 5-7atm after dropping is completed, and carrying out a reaction for 1-2 so as to obtain a mixture M2; 3) putting a hydrochloric acid solution into the mixture M2, controlling the reaction temperature to 80-90 DEG C and t he reaction pressure to 2-3atm, and carrying out a reaction for 40-60min so as to obtain a mixture M3; and 4) putting an alkali 2 into the mixture M3 to adjust the pH value to 4, controlling the temperature to be less than 70 DEG C, cooling, leaving to stand and layer, washing an organic phase withwater, drying with a drying agent, and concentrating and evaporating off the solvents, thereby obtaining a product. The method is simple in operation, and no toxic substance is used.
Sustainable poly(ether amide)s from lignin-derived precursors
Saenz, Guery,Scott, Colleen
, p. 2154 - 2160 (2018/10/05)
In recent years, there have been concerted efforts to replace petrochemical products with those from renewable sources due to the unsustainability of petroleum feedstock, and the continued volatility in the price. This work describes the synthesis and thermal properties of two new lignin-derived poly(ether-amide)s as alternative thermoplastics to petroleum-based commodities. Poly-4-(2-aminoethoxy)benzoate (PEAB) and poly-4-(2-aminoethoxy)-3-methoxybenzoate (PEAV) are synthesized by a melt polycondensation and characterized by 1H NMR spectroscopy and thermal analysis. The number average molecular weight (Mn) of the polymers are estimated from the 1H NMR spectroscopy analysis, and were shown to be 4100 and 12,000 g/mol for PEAB and PEAV respectively. The PEAB had a higher decomposition temperature (Td) as well as glass transition temperature (Tg) compared to PEAV; albeit, with a lower molecular weight. The polymers’ Td were in the range of 330 °C–380 °C and the Tg were between 100 °C and 120 °C. The thermal properties of the polymers are in the desirable range for thermoplastic materials used in the packaging, storage, and coating industries. Furthermore, the polymers are susceptible to degradation under acidic conditions in a short period; a property that is highly desirable for degradable polymers.
