Purification of tetrahydrofuran Warning

Propanol with magnesium in reduction of chlorobenzene, 47, 104 Propionyl fluoride, 46, 6 n Propylamine, 46, 85 n Propylhydrazine, 46, 85 C ( Propyl) N phenylmtrone, genera tion from phenylhydroxylamme and n butyraldehyde, 46, 97 Purification of tetrahydrofuran (Warning), 46,105 4H Pyran 4-one, 2 6 dimethyl 3,5 diphenyl, 47, 54... 

Tctrahydrofuran (purchased from Fluka AG or J. T. Baker Chemical Company) is distilled from sodium hydride prior to use. For warnings regarding the purification of tetrahydrofuran, see Org. Syn., Coll. Vol. 5, 976 (1973). 

Technical grade tetrahydrofuran was predried for a few days over sodium hydroxide. It was then heated under reflux over sodium wire with benzophenone until it developed a permanent blue color and distilled with exclusion of atmospheric moisture. [Caution See Org. Syntheses, 46, 105 1966), for a warning regarding purification of tetrahydrofuran.]... 

The ethylmagnesium bromide is prepared in dry tetrahydrofuran and stored no longer than 1 week in a 250-ml. tube fitted with a 3-way vacuum stopcock and a dropping buret. The solution is decanted into the buret, and the correct volume is transferred to the reaction flask with positive nitrogen pressure. The tetrahydrofuran is purified by distillation from lithium aluminium hydride. See Org. Syn., 46, 105 (1966), for warning regarding the purification of tetrahydrofuran. 

Tetrahydrofuran is dried by distillation from lithium aluminum hydride. (See Org. Syn., 46, 105 (1966) for warning note regarding the purification of tetrahydrofuran.)... 

The checkers used reagent-grade tetrahydrofuran (available from Fisher Scientific Company) from a freshly opened bottle. The submitters used tetrahydrofuran purified as described in L. F. Fieser, Experiments in Organic Chemistry, 3rd ed., Revised, D. C. Heath and Co., Boston, 1957, p. 292. (See Org. Syn., 46, 105 (1966) for a warning regarding the purification of tetrahydrofuran.)... 

Tetrahydrofuran (THF) was distilled from lithium aluminum hydride under nitrogen (Caution See Org. Synth., Coll., Vol. V1973, 976 for a warning regarding the purification of tetrahydrofuran. The checkers employed THF that had been purified by distillation from sodium and benzophenone.). 

Reagent grade tetrahydrofuran available from Fisher Scientific Company was used by the checkers. For warning regarding the purification of tetrahydrofuran see Org. Syntheses, 46, 105 (1966). 

---