Tetramethylene sulfide

Dry hydrogen bromide [Org. Syntheses Coll. Vol. 2, 338 (1943)] is passed into tetrahydrofuran [Org. Syntheses Coll. Vol. 2, 566 (1943)] under a reflux condenser until the temperature of the reaction mixture reaches 150°, at which point the theoretical quantity of hydrogen bromide has been taken up. The reaction mixture is steam-distilled, and the distillate is extracted with ether. Distillation of the ethereal solution after drying gives a 63% yield of tetra-methylene bromide, b.p. 62-63°/3 mm. 

Fifty milliliters of 95% ethanol is heated to reflux in a flask equipped with two dropping funnels, a stirrer, and a condenser. In one funnel is placed 54 g. (0.25 mole) of tetramethylene bromide (p. 271) in 100 ml. of ethanol, and in the other a solution of 60 g. (0.25 mole) of sodium sulfide nonahydrate in a mixture of 100 ml. of ethanol and 50 ml. of water. The two solutions are added at such a rate that the additions are completed at the same time. About 3 hours is required to add the reagents, and the mixture is stirred and heated under reflux for an additional 6 hours. The same amounts of reagents 

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Trofimov and coworkers19 studied the yields of the radicals by ESR in the radiolysis at 100-110 K of diphenyl sulfoxide and tetramethylene sulfoxide. They found for tetramethy-lene sulfoxide a higher yield of radicals (G = 1.8) than for tetramethylene sulfide (G = 0.45). 

Tetramethyl glycol, b457 Tetramethylene oxide, t69 Tetramethylene sulfide, t87 Tetramethylethylene glycol, d569... 

This is well illustrated by the case of tetrahydrothiophene. This monomer cannot be polymerized at ambient temperatures because AG , calculated from a ringstrain of 2.0 kcal (50) and assuming AS equal to —20 cal K-1 mol-1 has a value of +4.0 kcal at 300 °K which would correspond to an equilibrium monomer concentration of more than 1G2 mol l-1, a value that can never be obtained. Inversely, poly-(tetramethylene sulfide), prepared by polycondensation, should degrade to form tetrahydrothiophene when the reactive species, necessary to allow this degradation, are introduced in the polymer. It was indeed shown that addition of a catalytic amount of triethyloxonium tetrafluoroborate to a solution of poly(tetramethy-lenesulfide) resulted in degradation of the polymer with formation of tetrahydrothiophene (51). 

Symmetrical sulfides are obtained in 70-90% yields by refluxing aqueous alcoholic solutions of halides with sodium sulfide. The nonahydrate of sodiiun sulfide is a satisfactory reagent for the reac-tion. Tetramethylene and pentamethylene halides give cyclic sulfides, e.g., tetramethylene sulfide (tetrahydrothiophene) (64%). Halides containing several other important functional groups have been employed. Typical examples include methallyl chloride, and halides with hydroxyl, ethoxyl, carboxyl, and diethylamino groups in the beta position. A dry synthesis of phenyl sulfide from calcium oxide, sulfur, and chlorobenzene at 300° has been reported. ... 

Tetrahydrothiophene (tetramethylene sulfide) gives tetramethylene sulfoxide in 90% yield on refluxing for 2 h with tetrabutylammonium periodate [776]. The oxidation of tetramethylene sulfide with one equivalent of hydrogen peroxide at room temperature affords tetramethylene sulfoxide with two equivalents at refluxing temperature, tetramethylene sul-fone is obtained (equation 559) [164]. 

To a flask containing 8.8 gm (0.1 mole) of tetramethylene sulfide is added in one portion 22.8 gm (0.2 mole) of 30% hydrogen peroxide. The reaction is exothermic and after 1 hr the solution becomes homogeneous. The solution is refluxed for 4 hr and then water is distilled off over a 1-hr period. The remaining solvent is stripped off under reduced pressure to leave 11.7 gm (97%) of colorless tetramethylene sulfone, mp 10°-10.5 C. 

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