Tetrahydrofurfuryl bromide

The procedure given above is essentially the method of Paul.1 The interaction of tetrahydrofurfuryl bromide and sodium amide... 

Two small portions of benzene are used for rinsing the flask. The benzene is distilled by reducing the pressure gradually to about 60 mm. and heating the flask gently in an oil bath (not above 90°). After the benzene has been removed, the pressure is reduced to 5-10 mm. and the bath is heated slowly to 150-155° until no more material distils (Note 2). The crude distillate (110-126 g.) is redistilled through an efficient column, and the purified tetrahydrofurfuryl bromide is collected at 69-70°/22 mm. (61-62°/13 mm., 49-50°/4 mm.) (Note 3). The yield is 90-102 g. (53-61 per cent of the theoretical amount). 

Tetrahydrofurfuryl bromide has been obtained in low yields by the action of hydrobromic acid, or of phosphorus tribromide, on the corresponding alcohol.1 The yield is improved markedly by use of phosphorus tribromide and pyridine.2 3 The bromide has also been prepared by the action of potassium hydroxide on 4,5-dibromopentanol-l.4... 

Tetrahydrofurfuryl chloride has been prepared from the alcohol and thionyl chloride 3 or phosphorus trichloride. 4-Penten-l-ol has been prepared from tetrahydrofurfuryl bromide or chloride and magnesium or sodium.4 6... 

Tetrahydrofurfuryl bromide, 23, 88 Tetrahydrofurfuryl chloride, 25,84 /3-(Tetrahydrofuryl)-propionic acid,... 

Tetrahydrofurfuryl bromide, for instance, is obtained by dropping tetrahydrofurfuryl alcohol (1 mole) and dry pyridine (5 g) into PBr3 (0.36 mole), dry pyridine (15 g), and dry benzene (50 ml) at — 5° (ice-salt cooling) and allowing reaction to proceed for 24-48 h at room temperature.930... 

Other examples of the use of this method include the preparation of tetrahydrofurfuryl bromide, 3a-cholestanyl bromide (using THF as solvent, 85% yield), and intermediates toward the syntheses of alkaloids (eqs 4 and 5). The reaction of the reagent with DMF alone generates the formamidinium salt which can ultimately result in the isolation of the formate ester derivative of the alcohol substrate (eq 6). It is therefore important that the N-halosuccinimide is added last for the preparation of alkyl halides. Other solvents used for this reaction include CH2CI2 (which can facilitate the workup of the reaction products) and HMPA. ... 

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