Chloro to mercapto

Addition of hydrogen sulfide to epichlorohydrin is reported t<> follow one of two courses depending on temperature, 8i,uw Whereas 3-chloro-l-mercapto-2-propanol is formed at 0°, a chlorine-free sub stance is secured at 60% which has been formulated on the baeis of its ... 

The 1,1-dioxide of 3-halomethyl-2,3-dihydropyrido[l,2,3-de]-l,4-benzo-thiazinium triiodide and bromide were prepared by cyclization of 8-allyl-sulfonylquinoline with I2 in 2-PrOH, and with Br2 in CHCI3 (93MI9). When 8-[(l-chloro-2-mercapto-2-propyl)thio]quinoline HC1 was left to stand in EtOH at 20°C 2-mercapto-2-methyl-2,3-dihydropyrido[l,2,3-de]-l,4-benzothiazinium chloride was obtained (94ZOR636). 8-[2-Chloro-l-(un)-substituted ethylthio]quinolines could easily cyclized to 2,3-dihydropyrido-... 

Halomercaptans are converted to thietanes by treatment with a as exemplified by the formation of 3-hydroxythietane 21 from 3-chloro-l-mercapto-2-propanol 20 4-thiocyano-2-pentanol 22 is converted to a mixture of cis- and trans-2,4-dimethylthietane 23 by treatment with sodium hydride. The latter reaction involves displacement of cyanate ion by the mercaptide ion. 2,2,4-Trimethylthietane was also prepared by this method. 

Acetamido-5-mercapto-l, 3,4-thiadiazole is prepared as described under acetazolamide. This on treatment with/>-chlorobenzyl ehloride forms the corresponding />-chloro benzyl mercapto derivative, which when reacted with methyl bromide in the presenee of sodium methoxide yields the acetylamino thiadiazoline derivative. On oxidation with aqueous ehlorine it gives rise to the 2-sulphonyl chloride derivative which finally yields methazolamide on amidation with ammonia. 

Other sulfur compounds such as thiourea, ammonium dithiocarbamate, or hydrogen sulfide also lead to 2-mercaptothiazoles. Thus thiourea has been used in the syntheses of 4,5-dimethyl (369) and 4-aryl-2-mercapto-thiazoles (Table 11-30) (519). The reactions were carried out by condensing the ia -thiocyanatoketones with thiourea in alcohol and water acidified with hydrochloric acid. By this procedure, 4-aryl-2-mercaptothiazoles were obtained in yields of 40 to 80% with bis-(4-aryl-2-thiazolyl) sulfides as by-products (519). These latter products (194) have also been observed as a result of the action of thiourea on 2-chloro-4-arylthiazole under the same experimental conditions. They can be separated from 2-mercaptothiazoles because of their different degrees of solubility in sodium hydroxide solution at 5%. In this medium bis-(4-phenyl-2-thiazolyl)sulfide is... 

The behavior of the 2-mercapto-4-arylthiazoles in this reaction would seem to be analogous to that of the 2-mercaptobenzothiazoles (137). It appears that monosulfide compound (195) cannot be obtained from 2-chloro- and 2-mercapto-4-phenylthiazoles (given the difficulty of preparing it in this way) but rather by the action of the 2-mercapto-4-phenyl-thiazole on the intermediary, 4-phenyl-2-isothiazolyl isothiouronium chloride (194), as in Scheme 101. 

Hydroxy and mercapto substituents at the 3- and 5-positions can also exist in tautomeric forms (see Section 4.01.5.2) and can be alkylated at either the substituent or the ring nitrogen atom. 3-Methoxy groups are not replaced by nucleophiles, but both 3- and 5-alkylthio groups react readily, as does 3-methoxy-l,2-benzisothiazole. Alkylthio compounds can be oxidized to sulfoxides and sulfones, and the latter readily undergo nucleophilic replacement. All the hydroxy compounds react with phosphorus pentachloride to give the chloro derivatives. 

Related reactions are those of sodium azide with carbon disulflde to give 5-mercapto-l,2,3,4-thiatriazole (see 8ection IV) and with thio-carbonyl chloride to give 5-chloro-l,2,3,4-thiatriazole. ... 

Substituents in the 6-position (cf. 267) show appreciable reactivity. 6-Bromo-as-triazine-3,5(2j, 4j )-dione (316) undergoes 6-substitution with secondary amines or hydrazine, with mercaptide anions or thiourea (78°, 16 hr), with molten ammonium acetate (170°, 24 hr, 53% yield), and with chloride ion during phosphorous oxychloride treatment to form 3,5,6-trichloro-as-triazine. The latter was characterized as the chloro analog of 316 by treatment with methanol (20°, heat evolution) and hydrolysis (neutral or acid) to the dioxo compound. The mercapto substituent in 6-mercapto-as-triazine-3,5(2iI,4if)-dione is displaced by secondary... 

Chloro-3-nitrocoumarin (81) was found to react easily with 2-mercapto-aniline (319) to give the corresponding denitrocyclization product 348 (Eq. 31) (85H2539). 

Kinetic studies have been carried out on the displacement reactions of various chloroazanaphthalenes with ethoxide ions and piperi-dine. - 2-Chloroquinoxaline is even more reactive than 2-chloro-quinazoline, thus demonstrating the powerfully electrophilic nature of the -carbon atoms in the quinoxaline nucleus. The ease of displacement of a-chlorine in the quinoxaline series is of preparative value thus, 2-alkoxy-, 2-amino-, - 2-raethylamino-, 2-dimethyl-amino-,2-benzylamino-, 2-mercapto-quinoxalines are all readily prepared from 2-chloroquinoxaline. The anions derived from substituted acetonitriles have also been used to displace chloride ion from 2-chloroquinoxaline, ... 

N-(m-methylmercapto-phenyl)-aniline (MP 59° to 61°C) is prepared by condensing m-methyl-mercapto-aniline (BP 163° to 165°C/16 mm Hg) with the potassium salt of o-chloro-benzoic acid and decarboxylating the resultant N-(m-methylmercapto-phenyl)-anthranilic acid (MP 139° to 141°C) by heating, and then distilling. 

When two polymers interact or react with each other, they are likely to provide a compatible, even a miscible, blend. Epoxidized natural rubber (ENR) interacts with chloro-sulfonated polyethylene (Hypalon) and polyvinyl chloride (PVC) forming partially miscible and miscible blends, respectively, due to the reaction between chlorosulfonic acid group and chlorine with epoxy group of ENR. Chiu et al. have studied the blends of chlorinated polyethylene (CR) with ENR at blend ratios of 75 25, 50 50, and 25 75, as well as pure rubbers using sulfur (Sg), 2-mercapto-benzothiazole, and 2-benzothiazole disulfide as vulcanizing agents [32]. They have studied Mooney viscosity, scorch... 

Absorption spectra of formazans have been studied in detail. Almost all formazans exhibit UV/visible spectra between 300 and 600 nm.1,2,12,13,40,62,325 326 The absorption maxima are very sensitive to substituent effects. For example, the 1,5-diphenyl formazan 185 when X is hydrogen, methyl, phenyl, cyano, and mercapto shows a band at 420, 410, 470, 504, and 590nm in ethanol, respectively. The 3-chloro derivative 186 when X is hydrogen, iodine, bromine, chlorine, and fluorine has a band at 433,433,430,421, and 417 nm, respectively. Table 13 shows the influence of substituents on the absorption maxima in the trisubstituted formazans 3. Table 14 shows the influence of substituents on the absorption maxima of... 

V-(3-Chloro-4-fluorophenyl )amino(mercapto)methylenemalonate (344) was reacted with 4-methoxybenzyl chloride in the presence of potassium carbonate in acetonitrile at ambient temperature for 3 hr to give AM3-chloro- 4 -fluorophenyl)amino[ (4-methoxybenzyl)thio]methy lenemalonate (345) in 81% yield (82EUP58392). 

Another synthetic approach to the octahedral complexes of type (252) is provided by the thermal decomposition of the hydrido complex [ReH7(PPh3)2] in the presence of 2-mercapto-quinoline or 2-hydroxyquinoline in 1,2-dichloroethane solutions. The solvent is source of the chloro ligands and, thus, essential for the formation of the rhenium(III) products. Comparable reactions in THF afford hydridorhenium(V) complexes (see Section 5.3.2.11). 

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