模拟移动床色谱分离二十碳五烯酸乙酯和二十二碳六烯酸乙酯

二十碳五烯酸和二十二碳六烯酸是两种非常重要的ω-3多不饱和脂肪酸,广泛用于膳食补充剂和药品,同时它们的生理作用并不完全相同,因此分离制备它们的高纯度单体十分必要。首先以聚苯乙烯/二乙烯基苯（PS/DVB）聚合物为固定相,在液相色谱上分离二十碳五烯酸乙酯（EPA-EE）和二十二碳六烯酸乙酯（DHA-EE）,考察了流动相、填料粒径、温度对分离的影响。然后采用粒径20 μ m、孔径10 nm的PS/DVB填料装填了8根150 mm×10 mm的半制备色谱柱,测定了半制备柱装填的均一性。最后尝试在模拟移动床（SMB）色谱上分离EPA-EE和DHA-EE的混合物,探究了Ⅱ区和Ⅲ区的流量、进料流量、进料浓度对分离的影响,结果表明SMB制备的EPA-EE和DHA-EE的相对纯度分别为91.6%和93.6%,回收率分别为97.0%和91.6%,固定相生产率为5.97 g/（L\5h）,溶剂消耗为1.52 L/g。SMB制备EPA-EE和DHA-EE具有较大的应用潜力。     

对硝基苯甲酸乙酯的合成

以硫酸氢钾为催化剂,研究了对硝基苯甲酸和乙醇反应生产对硝基苯甲酸乙酯的合成工艺.考察了催化剂用量、反应时间、醇酸物质的量之比、带水剂用量以及催化剂重复使用次数对酯化率的影响,确定了最佳反应条件.当对硝基苯甲酸的用量为0.015mol,无水乙醇为0.060mol,反应时间为2.0h,带水剂环己烷用量为15mL,催化剂硫酸氢钾的用量为0.4g,对硝基苯甲酸乙酯的酯化率可达到91.65%.在此条件下,催化剂的催化活性高,反应条件温和,该合成方法简便,产品收率优良,催化剂可重复使用,且价格低廉.     

Reaction of methyl phenylphosphinate with tetracyclone in the presence of bases

Conclusions In the presence of amines methyl phenylphosphinate reacts to form products only of 1,6 addition to the conjugated system of tetracyclone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1602–1607, July, 1978.     

Impossibility of macrocyclization of resorcinol with the phenylphosphonous acid tetraethyldiamide

On the basis of resorcinol and phenylphosphonous acid tetraethyldiamide a series of new phosphorylated compounds was prepared for the first time. It was found that on the basis of these products the target macrocycle does not form either under mild or under rigid conditions because instead of macrocyclization oligomerization takes place.     

Electrolytic synthesis of nipecotic acid ethyl ester

An electrolytic method was suggested for the synthesis of nipecotic acid ethyl ester in a diaphragm electrolytic cell on a copper cathode in aqueous alcoholic alkali solution.     

Reaction of ethyl ester and nitrile of 5-methyl-2-furancarboxylic acid with mixture of nitric and sulfuric acids

The reaction of 70% HNO with ethyl 5-methyl-2-furancarboxylate in concentrated H₂SO₄ gave the corresponding 4-nitro derivative and ethyl 5-formyl-2-furancarboxylate. Only 4-nitro derivative, which was converted into amidoxime, was obtained from 5-methyl-2-furonitrile.Latvian Institute of Organic Synthesis, Riga LV-1006; e-mail: elmira@osi.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 168–170, February 2000.     

Reaction of methyl ester of n-methylimidoacetic acid with chloral

Russian Chemical Bulletin -     

Reaction of trifluororacemic acid methyl ester with 1,3-dienes

The reaction of trifluororacemic acid with 1,3-dienes affords Diels-Alder reaction products in a high yield and with a high degree of specificity. Catalysis by SnCl₄ changes the course of the reaction of the ester with isoprene, affording an ene reaction product.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 141–145. January, 1991.     

Reaction of o-diaminoanthraquinones with acetoacetic ester and crotonic acid

The reaction of 1,2 (and 2,3)-diamino-9,10-anthraquinones with acetoacetic ester and crotonic acid gave dihydro- and tetrahydroanthraquinonediazepinones, the structures of which were established on the basis of spectral data and chemical transformations.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1107–1112, August, 1982.     

Reaction of α-chloronitrosoalkanes with the trimethylsilyl ester of diphenylphosphonous acid

The reaction of - chloronitrosoalkanes with the trimethylsilyl ester of diphenylphosphonous acid leads to the formation of products of the Allen reaction, namely, phosphorylated oximes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 476–477, February, 1990.