2,2-DIPYRIDYL DISULFIDE

DPPA has been used for the direct C-acylation of methyl isocyanoacetate with carboxylic acids to give 4-methoxycarbonyloxazoles. t-Daunosamine, the glycone component of anticancer anthracycline antibiotics, has been synthesized from L-lactic acid in 9 steps with a 24% overall yield, where a key step in the sequence is the direct C-acylation of methyl isocyanoacetate with the lithium salt of the lactate ester using diphenyl phosphorazidate (eq 7). 

Albert V. Thomas Abbott Laboratories, North Chicago, IL, USA 

Form Supplied in white (colorless) crystalline solid. 

Preparative Methods although 2,2 -dipyridyl disulfide is commercially available, it can be readily prepared from 2-pyridinethione by oxidation with a number of reagents.  

Handling, Storage, and Precautions the solid is irritating to eyes, mucus membranes, and respiratory tract, and physical contact should be avoided. Combustion produces toxic byproducts including nitrogen oxides. Cold storage in air-tight containers is recommended. Use in a fume hood. 

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Cathepsin B (from human liver) [9047-22-7] Mr 27,500 [EC 3.4.22.1]. Purified by affinity chromatography on the semicarbazone of Gly-Phe-glycinal-linked to Sepharose 4B, with elution by 2,2 -dipyridyl disulfide [Rich el al. Biochem J 235 731 1986 Methods Enzymol 80 551 1981]. 

In these papers, the carboxylic acid to be protected was a stable, unsubstituted compound. Harsh conditions were acceptable for both formation and cleavage of the amide. Typically, a simple secondary amide is very difficult to cleave. As the pKa of the conjugate acid of an amide decreases, the rate of hydrolysis of amides derived from these amines increases. The dimethylamide of a cephalosporin was prepared as follows using 2,2 -dipyridyl disulfide. ... 

Additional acceleration of acylation can be obtained by inclusion of cupric salts, which coordinate at the pyridine nitrogen. This modification is useful for the preparation of highly hindered esters.122 Pyridine-2-thiol esters can be prepared by reaction of the carboxylic acid with 2,2 -dipyridyl disulfide and triphenylphosphine123 or directly from the acid and 2-pyridyl thiochloroformate.124... 

Unfortunately, 2,2 -dipyridyl disulfide is relatively insoluble in aqueous buffers. The use of this compound to modify molecules usually involves prior dissolution in an organic solvent... 

Figure 1.123 2,2 -Dipyridyl disulfide reacts with thiols to form an active pyridyl disulfide intermediate.

A. Svenson, A rapid and sensitive spectrophotometric method for determination of hydrogen sulfide with 2,2 -dipyridyl disulfide. Anal. Biochem. 107, 51-55 (1980). 

Scheme 17 Completion of Kang s synthesis of lb. Reagents and conditions a (i) 103,2,4,6-trichlorobenzoyl chloride, Et3N, THF, rt, (ii) 109, DMAP, benzene, rt, 90% b BU4NF, THF, rt, 94% c TEMPO, NaCl02, NaH2P04 buffer (pH 6.7),NaOCl,MeCN,rt,91% d (i) 2,2 -dipyridyl disulfide, Ph3P, MeCN, (ii) CuBr2, MeCN, rt, 62% e (i) H2,10% Pd/C, MeOH, rt, (ii) aq. CH2O, HOAc, rt, 89%...

Macrolactonization of CD-hydroxyl-acid using 2,2 -dipyridyl disulfide. Also known as Corey-Nicolaou double activation method. 

LACTAMS Di-n-butyltin oxide. Ily-droxylamine-O-sulfonic acid. Iodine azide. Sodium eyanoborohydride. (3-LAC TAMS Cyanuric chloride. Grignard reagents. Ion-exchange resins. Lithium phenylethynolate. Sodium dicarbonyl-cyclopentadienylferrate. Titanium(lll) chloride. Titanium(IV) chloride. Tri-phenylphosphino-Carbon tetrachloride. Triphenylphosphine-Die thyl azodicar-boxylate. Triphenylphosphine-2,2 -Dipyridyl disulfide. 

Dipyridyl disulfide and bis(2-aminophenyl) disulfide do not undergo hydroxysulfenylation using Pb(OAc)4 or in the absence of a metal salt, but each reacts satisfactorily in the presence of catalytic amounts of copper(II) acetate.2... 

Benzylamino)acetonitrile, 29 4-Pyrrolidinopyridine, 262 Triphenylphosphine-2,2 -Dipyridyl disulfide, 332 Zinc iodide, 350 Lactonization (see also Enol lactonization)... 

Copper Compounds Bis(acetonitrile)chloronitropalla-dium(II)-Copper(II) chloride, 33 t-Butyllithium-Copper(I) bromide-Di-methyl sulfide, 58 Copper(II) acetate-Bis(2-amino-phenyl) disulfide, 156 Copper(II) acetate-2,2 -Dipyridyl disulfide, 156... 

The lithiated dimethoxybenzene reaction with 2,2-dipyridyl disulfide produced 2,5-dimethoxyphenyl 2-pyridyl sulfide which distilled at 135-150 °C at 0.4 mm/Hg and could be recrystallized from cyclohexane containing 2% EtOH to give aproduct thatmelted at 66-67.5 °C. Anal. (CnHnNO,S) C,H. This would have produced 2,5-dimethoxy-4-(2-pyridylthio)phenethylamine (2C-T-10) but it was never pursued. 

Dipyridyl Disulfide (Aldrithiol, Corey Reagent) Aldrichimica Acta 1971, 4,33... 

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