Benzophenone, sodium ketyl

Ethyl ether is freshly distilled from sodium/benzophenone ketyl at atmospheric pressure under nitrogen. 

Toluene (99.9%) is purchased from Fisher and dried by distillation under argon from sodium benzophenone ketyl. 

The submitters used THF that was freshly distilled over Na/K alloy NMP was distilled over CaH2. The checkers used commercially available anhydrous THF and NMP obtained from Aldrich Chemical Co. There appears to be a slight increase in yield when THF distilled from sodium/benzophenone ketyl is used instead of the commercial THF. All other solvents used were of reagent grade quality and were used without further purification. 

Tetramethydisiloxane was purchased from Lancaster Synthesis Inc. and used as received. THF was obtained from Mallinckrodt Inc. and freshly distilled from sodium/benzophenone ketyl. 

Tetrahydrofuran (THF) was distilled from sodium/benzophenone ketyl under a nitrogen atmosphere. 

The checkers dried and purified the dioxane by distillation from the sodium-benzophenone ketyl. 

Sodium benzophenone ketyl Benzophenone, radical ion (1 —), sodium (8) Methanone, diphenyl-, radical ion (1-), sodium (9) (3463-17-0)... 

Most polymerizations were carried out in tetrahydrofuran (THF) (Fisher, Certified Grade) which had been previously distilled from the purple sodium/benzophenone ketyl. 

S)-Ethyl lactate, [other chemicals employed in this procedure were obtained from Aldrich Chemical Company, Inc. Anhydrous tetrahydrofuran was prepared by distillation under argon from sodium benzophenone ketyl. 

Tetrahydrofuran is distilled from sodium-benzophenone ketyl under argon. The reaction may be carried out using a freshly opened can of anhydrous diethyl ether from Fisher Scientific or Mallinckrodt without further purification. 

Tetrahydrofuran is freshly distilled from sodium benzophenone ketyl. 

The tetrahydrofuran was dried by distilling from lithium aluminium hydride and then from sodium benzophenone ketyl (generated by adding small pieces of sodium metal and benzophenone) directly into the reaction flask. A blue-black color of the ketyl solution indicates dryness. The checkers purified tetrahydrofuran by distillation from sodium hydride dispersion under nitrogen, and used it immediately. 

Tetrahydrofuran and 1,2-dimethoxyethane were dried and deoxygenated by distillation from sodium benzophenone ketyl under argon. 

Benzene is reagent grade quality and distilled from sodium/benzophenone ketyl. This solvent is a suspect carcinogen and should be handled in a well-ventilated hood. 

Tetrahydrofuran was distilled under nitrogen from sodium/benzophenone ketyl radical immediately prior to use. 

Materials. Boron trichloride (Aldrich), sodium tetraphenylborate (Aldrich), and cobaltocene (Strem) used as received. 9-Hydroxy-l-oxophenalene synthesized according to literature procedures.Toluene was distilled from sodium benzophenone ketyl immediately before use. Acetonitrile was distilled from P2O5 and redistilled from CaH immediately before use. 

Dimethoxyethane was obtained from Aldrich Chemical Company, Inc., and distilled from sodium benzophenone ketyl immediately before use. 

The ether was freshy distilled from sodium benzophenone ketyl. The checkers used anhydrous ether from a freshly-opened can. 

Toluene is first distilled from sodium benzophenone ketyl under argon. Prior to the reaction, the toluene is degassed by performing two freeze-pump-thaw cycles, then the flask is backfilled with argon. 

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