10-Alkenylphenothiazines. 2. Synthesis and mechanism of acidic hydrolysis of cis- and trans-10-2-phenylvinyl)phenothiazines

1986 ◽  
Vol 22 (10) ◽  
pp. 1152-1157
Author(s):  
V. A. Anfinogenov ◽  
O. A. Napilkova ◽  
E. E. Sirotkina ◽  
V. D. Filimonov ◽  
A. I. Khlebnikov
1979 ◽  
Vol 57 (14) ◽  
pp. 1870-1876 ◽  
Author(s):  
Gerry Kavadias ◽  
Robert Droghini

Reaction of N,N′-diethoxycarbonyl-2,5-dideoxystreptamine (1b) with thionyl chloride produced the iminoether dihydrochloride 8 which, upon simple treatment with water gave the di-N,O-carbonyl compound 9. Acidic hydrolysis of 9 yielded the aminocyclitol 2a. Alternatively, 2a was prepared from N,N′-dibenzoyl-2,5-dideoxystreptamine (1c) via the oxazoline 10 followed by acidic hydrolysis. Treatment of 1c with triethyl orthoacetate in the presence of boron trifluoride etherate produced the oxazoline 11 and the latter product was hydrolyzed to give 3a. By the same reaction sequence, 1e and 1h were converted to the oxazolines 12 and 13 which upon acidic hydrolysis provided the enantiomeric aminocyclitols 4 and 5. Ring-opening reactions of cis- and trans-1,4-diepoxycyclohexanes (14 and 16) with sodium azide to the diazido compounds 15 and 17, followed by reduction, afforded the aminocyclitols 6 and 7.


2020 ◽  
Vol 153 (24) ◽  
pp. 244308
Author(s):  
Ali Abou Taka ◽  
Mark C. Babin ◽  
Xianghai Sheng ◽  
Jessalyn A. DeVine ◽  
Daniel M. Neumark ◽  
...  

2018 ◽  
Vol 6 (8) ◽  
pp. 10999-11007 ◽  
Author(s):  
Gongzhe Chen ◽  
Xicheng Wang ◽  
Yijun Jiang ◽  
Xindong Mu ◽  
Haichao Liu

1980 ◽  
Vol 63 (5) ◽  
pp. 1049-1051
Author(s):  
Juan A Squella ◽  
Luis J Nunez-Vergara ◽  
Maximo Aros

Abstract Polarographic and spectrophotometric methods are proposed for the determination of ampicillin in capsules. Acidic hydrolysis of ampicillin with 1% HCHO in 0.3N HCl yields a degradation product identified as 2-hydroxy-3-phenyl-6-methylpyrazine. This compound has a well defined UV absorption band at 380 nm and a polarographic wave at –0.55 V vs SCE, which can be used for analytical purposes. Individual capsule assays, composite assays, and recovery studies are described. The average recovery values and standard deviations (SD) for UV and polarographic determinations were 99.20% (SD 0.95) and 100.85% (SD 1.09), respectively


ChemInform ◽  
1987 ◽  
Vol 18 (31) ◽  
Author(s):  
M. SCHLEUDER ◽  
S. BUTZKI ◽  
P. RICHTER ◽  
A. SOKOLOV

1986 ◽  
Vol 17 (8) ◽  
Author(s):  
V. V. NURGATIN ◽  
B. M. GINZBURG ◽  
V. I. KOVALENKO ◽  
G. A. MARCHENKO

2020 ◽  
pp. 174751982094835
Author(s):  
Xiao-Lin Qiu ◽  
Qing-Feng Zhang

The acidic hydrolysis of astilbin to produce its aglycone, taxifolin, was investigated in this study. The effects of aq. HCl concentration and temperature on the reaction were studied, and the kinetic parameters were calculated. The results showed that with higher aq. HCl concentration and temperature, the hydrolysis of astilbin became faster. The activation energy of the hydrolysis reaction under 1 mol L−1 aq. HCl was calculated with a value of 148.6 kJ mol−1. The reaction was successfully applied to produce taxifolin from a sample of Rhizoma Smilacis Glabrae. A simple method for the purification of taxifolin from Rhizoma Smilacis Glabrae was developed with purity of 97.5%.


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