Cl. 260-484 11 Claims ABSTRACT OF THE DISCLOSURE Solutions of 0t-S11bSl-lt11t6d dor l-arylacetic acid salts of asymmetric optically active nitrogeneous bases are heated to elevated temperatures to cause racemization. By repeated crystallization and racemization steps with final conversion to the ...
Ultraviolet absorption spectra are recorded of cis- and trans- cinnamic acid, of cis- and trans- 1,2,3,4,-tetrahydronaphthylidene (1) acetic acid and of cis- and trans-尾 -(naphthyl-1) acrylic acid. The cis isomers all show a lower extin... E Havinga,RJF Nivard - 《Recueil Des ...
The paper also studied the separation of the two isomers by HPLC using -CD and Glucosyl--CD as a mobile phase additive in order to elucidate the mechanism of the separation process. 展开 关键词: madecassoside madecassic acid isomer HPLC cyclodextrin ...
α-ethyl-2-O-1-pyrrolidinylacetic acid has good linear relationship in the concentration range of 0.2-4.0 mg· mL-1 ( r=0.999 );the detection limit(S/N=3)was 5.3 μg·mL-1;the quantitative limit(S/N=10)was 20.1 μg·mL-1;each of optical isomers was well isolated.Conclusion:This ...
摘要: In doses of ten milligrams each, d-amphetamine, l-amphetamine, and d-desoxyephedrine delay the emptying of the stomach in the human. l-Desoxyephedrine is without effect.关键词: AMPHETAMINE/effects SALICYLIC ACID/derivatives STOMACH/physiology ...
The method was carried out by using a Polaris C18 column with a gradient solvent system of 0.5% acetic acid aqueous solution–acetonitrile. Seven target analytes including isodensifloside, isothyrsifloside, densifloside, thyrsifloside, scoparone, ayapin and scopoletin were exclusively identified ...
Direct separation of optical isomers of propranolol by HPLC method. Naproxen ( S )-6-methoxy-伪-methyl-2-naphthyleneacetic acid, is a non-steroidal anti-inflammatory drug, which is administered as a single enantiomer. Two d... 菅野,智,高橋,晴美,義村,尚美,... - 《Rinsho Yakuri/japanese...
The pH of sample solution was maintained with the addition of a buffer solution of acetic acid/acetate and was kept at 4.5. The other main experimental factors influencing the separation and preconcentration effect were systematically examined, such as the cartridge temperature, injection time, ...
production methodin the presence of acetic anhydride and concentrated sulfuric acid, obtained from the reaction of acetic acid and N-pentanol. Acetic acid, pentanol, acetic anhydride were added first, then concentrated sulfuric acid was added, and then heated and refluxed for 8H. After cooling, ...
There are many ways to prepare PROHYDROJASMON, which can be obtained through the esterification reaction of isobutyl acetic acid and isovalerate, and then through redox reaction. In addition, it can also be prepared by olefination of toluene. ...