Di-o-nitrophenyl disulfide

Di-o-nitrophenyl disulfide was first prepared by the action of hydriodic acid on o-nitrobenzene sulfochloride.1 It has also been prepared by the reduction of o-nitrobenzene sulfinic acid with hydrogen bromide 2 by the reduction of ethyl-o-nitro-phenylsulfonacetate with ammonium sulfide 3 and by the deamination of 4,4,-diamino-2,2 -dinitrodiphenyldisulfide.4 The procedure given is the method of Blanksma5 as elaborated by Wohlfahrt.6... 

A) o-Nitrobenzenesulfonyl Chloride.—A 3-I. three-necked, round-bottomed flask is fitted with an efficient liquid-sealed stirrer, a reflux condenser, and an inlet tube for introducing chlorine well beneath the surface of the liquid. A glass outlet tube leads from the reflux condenser to the hood. In the flask are placed 200 g. (0.65 mole) of di-o-nitrophenyl disulfide (Org. Syn. Coll. Vol. 1, 215) 1 1. of concentrated hydrochloric acid (sp. gr. 1.18), and 200 cc. of concentrated nitric acid (sp. gr. 1.42). A stream of chlorine is passed into the mixture at the rate of about two bubbles per second, and the solution is warmed on a steam bath to 70°. In about thirty minutes the disulfide melts and the solution becomes orange-red in color. After the disulfide has melted, the heating and addition of chlorine are continued for one hour. The sulfonyl chloride is separated immediately from the supernatant liquid by decantation, washed with two 300-cc. portions of warm water (70°) and allowed to solidify. The water is drained from the solid mass as completely as possible. 

Orthanilic acid was first made by the reduction of nitro-benzenesulfonic acid by ammonium sulfide.2 This reduction has also been carried out electrolyticallv, and by the use of iron or zinc.3 The acid has also been made by the rearrangement of phenylsulfamic acid,4 by the action of sodium hypobromite upon potassium o-carbaminebenzenesulfonate,5 by the reduction of the mixed nitrobenzenesulfonic acids followed by separation of the isomers,6 by the action of methyl alcohol upon o-nitro-phenylsulfurchloride,7 by the action of acid upon diacetyl diphenylsulfamide,8 by the debromination of />-bromoaniline-e-sulfonic acid,9 by the reduction of 1,2,6-aminothiophenolsulfonic acid,10 and by the hydrolysis and reduction of e-nitrobenzene-sulfonyl chloride, which was obtained from di-o-nitrophenyl-disulfide.11... 

Zinc dust (20 g., 0.31 gram atom) is added slowly over a period of 30 minutes to a solution of 3.1 g. (0.01 mole) of di-(o-nitrophenyl) disulfide [Org. Syntheses Coll. Vol. 1, 220 (1941)] in 350 ml. of warm glacial acetic acid. The mixture is boiled until colorless. A smaller amount of zinc can be used with a longer reaction time. The mixture is diluted with 2 volumes of water, cooled, and filtered to give 2.8 g. (90%) of the zinc salt of o-aminothiophenol. 

For the preparation of di-o-nitrophenyl disulfide, Bogert and Stull9 treated o-nitrochlorobenzene with an alcoholic solution of sulfur in sodium sulfide and... 

Equimolar amounts of benzyloxycarbonyl-L-phenylalanine, ethyl glycinate, mercuric chloride, di-o-nitrophenyl disulfide, triphenylphosphine, and 2 moles tri-ethylamine in methylene chloride mixed 3 hrs. at room temp. ethyl benzyl-oxycarbonyl-L-phenylalanylglycinate. Y 89%. Also related condensation of sulfen-amides and cupric carboxylates s. T. Mukaiyama et al.. Am. Soc. 90, 4490 (1968). 

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