Homogeneous synthesis and characterization of chitosan ethers prepared in aqueous alkali/urea solutions

2018 ◽  
Vol 185 ◽  
pp. 138-144 ◽  
Author(s):  
Jinfeng Cao ◽  
Jun You ◽  
Lina Zhang ◽  
Jinping Zhou
Keyword(s):  
Aqueous Alkali ◽  
Synthesis And Characterization ◽  
Homogeneous Synthesis

Homogeneous synthesis and characterization of polyacrylamide-grafted cationic cellulose flocculants

2015 ◽  
Vol 133 (14) ◽  
pp. n/a-n/a ◽  
Author(s):  
Hairong Zhang ◽  
Haijun Guo ◽  
Bo Wang ◽  
Lian Xiong ◽  
Silan Shi ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Homogeneous Synthesis

Synthesis and characterization of derivatized capped porphyrins

1992 ◽  
Vol 70 (5) ◽  
pp. 1366-1374 ◽  
Author(s):  
Hang Tang ◽  
Tilak P. Wijesekera ◽  
David Dolphin
Keyword(s):  
Ethyl Ester ◽  
Acidic Medium ◽  
Aqueous Alkali ◽  
Synthesis And Characterization ◽  
Methyl Groups ◽  
Pyrrole Derivatives ◽  
Standard Methods ◽  
Hydrophobic Cavity ◽  
Thermal Decarboxylation

The syntheses of porphyrins carrying either a fully hydrophobic cavity with a benzene moiety (32a,b) or a polar cavity with an amidobenzene (32c–d) are described. Terephthaldehyde (1) was converted to benzene-bisalkanoic acids (8, 10) and nitrobenzene-bisalkanoic acids (13 and 16) by using standard methods. The corresponding diacid chlorides 17a–d were used to acylate two equivalents of a β-unsubstituted pyrrole, and the ketonic groups were reduced by diborane. Following the transformation of the nitro function to the acetamide, appropriate modifications of the ethyl ester functions afforded the key bisformylpyrroles 25a–d. The cyanoacrylate-protected formyl pyrrole derivatives were mono-chlorinated at the α-methyl groups and condensed with two equivalents of an α-unsubstitutued pyrrole to give the dipyrromethane dimers. Strong aqueous alkali caused saponification of the two ester groups and deprotection of the formyl functions to produce the dipyrromethane dimer 30, which, after thermal decarboxylation, was cyclized intramolecularly in acidic medium to give the porphyrins 32 (n = 4 or 5, X = H or NHCOCH3).

Homogeneous synthesis and characterization of quaternized chitin in NaOH/urea aqueous solution

2012 ◽  
Vol 87 (1) ◽  
pp. 422-426 ◽  
Author(s):  
Fuyuan Ding ◽  
Xiaowen Shi ◽  
Xiaoxia Li ◽  
Jie Cai ◽  
Bo Duan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Synthesis And Characterization ◽  
Urea Aqueous Solution ◽  
Homogeneous Synthesis

Synthesis and Characterization of the Three Dicyclopentapyrenes

1996 ◽  
Vol 61 (10) ◽  
pp. 3572-3572
Author(s):  
Lawrence T. Scott ◽  
Atena Necula
Keyword(s):  
Synthesis And Characterization
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