Synthesis of α,ω‐Bis(oxazolidinone)polyoxyethylene via a Lithium Bromide–Catalyzed Reaction of Oligoethylene Glycol Diglycidyl Ethers with Isocyanates

Abstract

The synthesis of bis(oxazolidinone)polyoxyethylene derivatives 2a -h from oligoethylene glycols diglycidyl ethers 1a -e and isocyanates is reported. The reaction was achieved by lithium bromide and tributylphosphine oxide. These bis-oxazolidinones may have important antibacterial activity.

Catalytic Annulation of Epoxides with Heterocumulenes by the Indium-Tin System

“…Instead of using carbon dioxide, the cyclic adducts of epoxides with isocyanates are highly in demand [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. To effect the reaction, various catalysts have been used such as lithium halides [ 36 , 37 , 38 , 39 , 40 , 41 , 42 ], quaternary ammonium salts [ 43 , 44 ], phosphonium salt [ 45 ], AlCl 3 [ 46 ], magnesium halides [ 47 ], tetraphenylantimony iodide [ 48 , 49 , 50 ] and the chromium(Salphen) complex [ 51 ]. These catalysts promoting reactions require relatively severe conditions (over 100 °C).…”

Bimetallic Aluminum(salen) Catalyzed Synthesis of Oxazolidinones from Epoxides and Isocyanates

“…In contrast to the corresponding reactions between epoxides and either carbon dioxide or carbon disulfide which are also catalyzed by complex 1 , no cocatalyst is needed for the reaction with isocyanates, and cocatalysts including tetrabutylammonium bromide were found to inhibit the reaction. Compared to previously reported catalysts for the synthesis of oxazolidinones from epoxides and isocyanates, − the use of complex 1 allows the use of aliphatic as well as aromatic isocyanates. Reactions can be carried out at lower temperatures than literature procedures which require the use of refluxing DMF, refluxing xylene, or a sealed system at 200 °C .…”

“…The reaction shown in Scheme has previous been shown to be catalyzed by species including: ammonium salts, lanthanide salts, − lithium halides, − magnesium halides, tetraphenylantimony iodide, − and trialkyltin halides. − However, both the regiochemistry (formation of 4 versus 5 ) and stereochemistry of the reaction (retention or inversion of epoxide 2 stereochemistry) should be controlled, and the reaction should accommodate a wide range of epoxides 2 and isocyanates 3 . In this respect it is notable that previous work has largely been restricted to mono-substituted epoxides and arylisocyanates and has often employed toxic catalysts.…”

One‐pot Three Component Synthesis of ω‐(oxathiolan‐2‐thion‐5‐yl)‐α‐oxazolidin‐2‐ones

“…In a previous work, we reported the synthesis of symmetrical bis‐oxazolidinone bridged with a polyoxyethylene chain via reaction of oligoethylene glycols diglycidyl ethers with simple isocyanate in the presence of catalytic amount of lithium bromide. In this context, we have described also in earlier paper the synthesis of symmetrical bis(cyclic dithiocarbonate) from the same diglycidyl ethers and carbon disulfide with the same catalyst.…”