Disulfides esters

Heterodetic cyclic peptides are peptides consisting only of amino acid residues, but the links forming the ring are not solely eupeptide bonds one or more is an isopeptide, disulfide, ester, etc. 

Disulfides RSSR can also be produced. Other sulfonic acid derivatives can be converted to disulfides. Esters, such as PhSAc, are converted to disulfides PhS—SPh with Clay an and microwave irradiation. Thiobenzoate derivatives PhSBz are similarly converted to PhS—SPh with SmU. In a similar manner, RS—S03Na is converted to RS—SR when heated with samarium metal in water. ... 

Diaryl disulfides and diselenides add to alkynes to afford the (Z)-l, 2-bis(ar-ylthio)alkenes 193 and (Z)-l,2-bis(arylseleno)alkenes 194. Under CO pressure, carbonylative addition takes place to give thio esters and the selenoketones 195[I07], The selenoketones are converted into the /J-seleno-a, 3-unsaturated aldehydes 196 by Pd-catalyzed hydrogenolysis with HSnBu3[108,109],... 

This type of synthesis, which was investigated by Cook and Heilbron (323) and Takahashi (393, 394) between 1947 and 1953, gives 5-aminothiazoles variously substituted in the 2-position by reacting an aminonitrile with salts and esters of dithioacids, carbon disulfide, carbon oxysulfide, and isothiocyanates under exceptionally mild conditions. 

Hydrazine as Nucleophile. Reaction of hydrazine and carbon dioxide or carbon disulfide gives, respectively, hydrazinecarboxyhc acid [471-31-8], NH2NHCOOH, and hydrazinecarbodithioic acid [471-32-9], NH2NHCSSH, in the form of the hydrazinium salts. These compounds are useful starting materials for further synthesis. For example, if carbon disulfide reacts with hydrazine in basic medium with an alkyl haUde, an alkyl dithiocarbazate ester is obtained in a one-step reaction ... 

Mercaptothiazolines ate obtained from the corresponding sulfate esters and carbon disulfide,... 

Chemical Properties The formation of salts with acids is the most characteristic reaction of amines. Since the amines are soluble in organic solvents and the salts are usually not soluble, acidic products can be conveniendy separated by the reaction with an amine, the unshared electron pair on the amine nitrogen acting as proton acceptor. Amines are good nucleophiles reactions of amines at the nitrogen atom have as a first step the formation of a bond with the unshared electron pair of nitrogen, eg, reactions with acid anhydrides, haUdes, and esters, with carbon dioxide or carbon disulfide, and with isocyanic or isothiocyanic acid derivatives. 

Xanthate esters are prepared by reaction of isopropyl alcohol and carbon disulfide [75-15-0]. Isopropyl xanthates have wide use ia mineral flotation (qv) processes, and sodium isopropyl xanthate [140-93-2], C4HyOS2Na, is a useful herbicide for bean and pea fields (see Herbicides) (30). 

A fermented-egg product (EEP), patented as an attractive bait for synanthropic flies, has been shown to be attractive to coyotes and repeUent to deer (79). Its components are variable, with relative concentrations of 77% fatty acids, 13% bases, and 10% (primarily) neutrals composed of at least 54 volatiles such as ethyl esters, dimethyl disulfide, and 2-mercaptoethanol. Synthetic formulations have been evaluated to find a replacement for a patented fermented-egg protein product that attracts coyotes and repels deer. Ten aUphatic acids (C-2 to C-8), four amines (pentyl, hexyl, heptyl, and trimethyl), dimethyl disulfide, 2-mercaptoethanol, and 54 more volatiles (C-1 to C-5 esters of C-1 to C-8 acids) have been tested as synthetic fermented egg (SEE) (80) in approximately the same proportions that are present in EEP. Weathering was a problem that caused decreased efficacy, which suggests trials of controUed-release formulations. Eourteen repeUents have been examined against white-taU deer in Peimsylvania in choice tests when treated onto sheUed com (81). 

General Reaction Chemistry of Sulfonic Acids. Sulfonic acids may be used to produce sulfonic acid esters, which are derived from epoxides, olefins, alkynes, aHenes, and ketenes, as shown in Figure 1 (10). Sulfonic acids may be converted to sulfonamides via reaction with an amine in the presence of phosphoms oxychloride [10025-87-3] POCl (H)- Because sulfonic acids are generally not converted directiy to sulfonamides, the reaction most likely involves a sulfonyl chloride intermediate. Phosphoms pentachlotide [10026-13-8] and phosphoms pentabromide [7789-69-7] can be used to convert sulfonic acids to the corresponding sulfonyl haUdes (12,13). The conversion may also be accompHshed by continuous electrolysis of thiols or disulfides in the presence of aqueous HCl [7647-01-0] (14) or by direct sulfonation with chlorosulfuric acid. Sulfonyl fluorides are typically prepared by direct sulfonation with fluorosulfutic acid [7789-21-17, or by reaction of the sulfonic acid or sulfonate with fluorosulfutic acid. Halogenation of sulfonic acids, which avoids production of a sulfonyl haUde, can be achieved under oxidative halogenation conditions (15). 

Several cellulose esters (qv) are prepared commercially. Cellulose xanthate [9032-37-5] is made by reaction of cellulose swollen in 8.5—12% sodium hydroxide solution (alkaU cellulose [9081-58-7J) with carbon disulfide and is soluble in the alkaline solution in which it is made. When such a solution, termed viscose, is introduced into an acid bath, the cellulose xanthate decomposes to regenerate cellulose as rayon fibers or cellophane sheets (see Fibers, REGENERATED CELLULOSICS). 

Treatment of 2-methylthiirane with t-butyl hydroperoxide at 150 °C in a sealed vessel gave very low yields of allyl disulfide, 2-propenethiol and thioacetone. The allyl derivatives may be derived from abstraction of a hydrogen atom from the methyl group followed by ring opening to the allylthio radical. Percarbonate derivatives of 2-hydroxymethylthiirane decompose via a free radical pathway to tar. Acrylate esters of 2-hydroxymethylthiirane undergo free radical polymerization through the double bond. 

Scheme 68 shows the conversion of the phenoxymethylpenicillin-derived disulfide (see Scheme 10) to penem derivative (91) (78JA8214). Of particular interest in this sequence is the reductive acylation step to afford (89) and the Wittig ring closure to give (90). The rate of the latter reaction was found to be greatly infiuenced by the steric and electronic character of both the thiol ester and the carboxyl blocking group. 

Sulfides orthio derivatives Metallic derivatives of thio ethers and disulfides, usually mixed with organic phosphite esters long-chain alkyl thienyl ketones Lubricating oils boiler water... 

Sulfur has also been added to the condensation product of enamines with cyanoacetic ester (575) and directly to enamines (576). A 2H-l,3-dithiol-2-thione was obtained from morpholinocyclohexene and tetramethylthiuram disulfide (577). 

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