Synthesis of oligo(ethylene glycol) toward 44-mer

Journal of Organic Chemistry

Volumn 71, Issue 26, 2006, Pages 9884-9886

  Ahmed, Saleh A ^a,b   Tanaka, Mutsuo ^a  

^a NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY AIST   (Japan)

^b Assiut University   (Egypt)

Author keywords

[No Author keywords available]

Indexed keywords

BENZYL GROUP; ETHYLENE GLYCOLS; WILLIAMSON'S ETHER SYNTHESIS;

BENZENE; ETHERS; ETHYLENE; GLYCOLS; HYDROGENATION; SYNTHESIS (CHEMICAL);

OLIGOMERS;

CHLOROFORM; ETHYLENE GLYCOL; FUNCTIONAL GROUP; OLIGO(ETHYLENE GLYCOL); OLIGOMER; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL REACTION; DEPROTECTION REACTION; ELIMINATION REACTION; GEL PERMEATION CHROMATOGRAPHY; HYDROGENATION; MESYLATION; MOLECULAR WEIGHT; PURIFICATION; SOLVENT EXTRACTION; SYNTHESIS; TOSYLATION; WILLIAMSON REACTION;

MOLECULAR STRUCTURE; MOLECULAR WEIGHT; POLYETHYLENE GLYCOLS;

EID: 33845928242     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo0617464     Document Type: Article

References (22)

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17. Both crude products contain tetra(ethylene glycol) bis(benzyl ether), which is formed at the monobenzyl protection step in ca. 10% molar ratio.
18. 3, respectively.
19. The mesylation of monobenzyl-protected tetra(ethylene glycol) under the same condition as the tosylation gave corresponding mesylate in low yield, and starting material was recovered. Therefore, pyridine was used as solvent and base.
20. 3 as eluent.
21. Purification for oligo(ethylene glycol) bis(benzyl ether) was performed by gel-permeation chromatography. On the other hand, most oligo(ethylene glycol)s were obtained in sufficient purity only by filtration off palladium carbon and evaporation of solvent.
22. In order to enhance product distribution to organic layer, 4-(dodecyloxy)benzyl group was adopted as a protecting group instead of benzyl group (see Supporting Information). In the synthesis of dodeca(ethylene glycol), yields for each steps with 4-(dodecyloxy)benzyl protecting group were similar to those with benzyl protecting group. However, purification of dodeca(ethylene glycol) bis(4-(dodecyloxy)benzyl ether) by gel-permeation chromatography was much easier, and purification of dodeca(ethylene glycol) was performed by solvent extraction where dodeca(ethylene glycol) and 4-(dodecyloxy)toluene distributed to aqueous and organic layers, respectively. This result implies that improvement in the purification process is possible by modification of the benzyl protecting group.