Benzyl-2,4-dinitrophenyl sulfide

B. 2,4-Dinitrobenzenesulfenyl chloride. Dry 2,4-dinitrophenyl benzyl sulfide (232 g., 0.80 mole) and 400 ml. of dry ethylene chloride are placed in a 2-1., one-necked, round-bottomed flask equipped with a stirrer (Note 3). Sulfuryl chloride (119 g., 0.88 mole) (Note 4) is added to the resulting suspension at room temperature. A mildly exothermic reaction causes the solid to dissolve quickly, usually within 1 to 2 minutes, with a temperature rise of 10-15° (Note 5). The resulting clear yellow solution is concentrated to an oil by heating under aspirator vacuum on a steam bath (Note 6). Caution Do not heat with gas or electricity because the product, like many nitro compounds, can explode if overheated.) The residual oil is cooled to 50-60°, and 3-4 volumes of dry petroleum ether (b.p. 30-60°) are added with vigorous handswirling. The oil quickly crystallizes. The mixture is cooled to room temperature and filtered to separate 2,4-dinitrobenzene-sulfenyl chloride as a yellow crystalline solid. The sulfenyl chloride is washed well with dry petroleum ether and dried at 60-80° (Note 7) weight 150-170 g. (80-90%) m.p. 95-96° (Notes 8, 9). 

Dinitrophenyl benzyl sulfide has been prepared by the reaction of benzyl chloride with 2,4-dinitrothiophenol2 or bis-(2,4-dinitrophenyl) disulfide2 and by the condensation of 2,4-dinitrochlorobenzene with benzyl mercaptan.4... 

The chlorinolysis of 2,4-dinitrophenyl benzyl sulfide gives a good yield of product which is satisfactory for most purposes without recrystallization. Only simple equipment and inexpensive materials are needed, only 2 or 3 hours of the operator s time are required, and the entire procedure can be completed within 24 homs. 

Benzyl isocyanide, 41, 14 Benzyl mercaptan for synthesis of 2,4-dinitrophenyl benzyl sulfide, 44, 48... 

A. 2,4-Dinitrophenyl benzyl sulfide. The apparatus consists of a 1-1., three-necked, round-bottomed flask equipped with a sealed... 

The 2,4-dinitrophenyl benzyl sulfide normally undergoes cleavage at room temperature without the addition of a catalyst. If the reaction does not occur spontaneously, the mixture may be warmed gently and/or one drop of dry pyridine may be added to initiate the reaction. 

Dinitrobenzenesulfenyl bromide may be similarly prepared by refluxing 2,4-dinitrophenyl benzyl sulfide with the equivalent amount of bromine in 5 parts of dry carbon tetrachloride. As it is less stable than the chloride, losing bromine if overheated, it should be concentrated on a 40° water bath under vacuum. When worked up in the same manner as the chloride, the product usually contains some is-(2,4r-dinitrophenyl) disulfide. Because the disulfide is insoluble in carbon tetrachloride, the sulfenyl bromide may be readily purified by recrystallization yield 75-80%, m.p. 102-104°. 

Benzyl 2,4-Dinitrophenyl Sulfide (Identification of Benzyl Mercaptan)... 

Procedure In a test tube containing a solution of 20 mg of benzyl 2,4-dinitrophenyl sulfide in 2 ml of acetic acid, hydrogen peroxide (0.3 ml) is added and the mixture is boiled gently for 2 min. After partial cooling an additional 0.3 ml of hydrogen peroxide is added and the mixture is boiled for a further 2 min. Water is then added until a colloidal precipitate is formed, and the mixture is allowed to stand in a refrigerator for 30 min. The separated sulfone is filtered off and washed twice with 1 ml of water. Yield, 23 mg mp, 168 —170 °C. Crystallization from 2 ml of methanol yielded 14 mg of the product, mp 177 —178 °C. A second crystallization from 1.5 ml of methanol left 8 mg of product, mp 181 — 182 °C. 

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