Sodium methanethiolate

Sodium methanethiolate [sodium methylmercaptide] [5188-07-8] M 70.1, pK 10.33 (MeS ). Dissolve the salt (lOg) in EtOH (lOmL) and add Et20 (lOOmL). Cool and collect the ppte, wash it with Et20 and dry it in vacuum. It is a white powder which is very soluble in EtOH and H2O. [Bull Soc Chim Fr 3 2318 1936.]... 

Sulfonium salt 103a also underwent ring-opening reactions with nucleophiles, such as NaBH4, sodium azide, and sodium methanethiolate, to afford trithiocins 107 (see Equation (30) and Table 18) <1996BCJ2349> and <1998BCJ1187>. 

Other methods that use 55 anions as precursor for the synthesis of fullerene-derivatives usually involve chemical formation of the anion. Alkylation of 55 has been accomplished, e.g. by reduction with propanethiol and potassium carbonate in DMF [91,92], sodium methanethiolate in acetonitrile [93], the naphthalene radical anion in benzonitrile[94], potassium naphthalide [95] or simply with zinc [96]. 

The stability of substituted 1,2-dithianes toward ring-opening polymerization was tested by heating the disulfides with a catalytic amount of sodium methanethiolate <1989T91> none of the 1,2-dithianes were stable with respect to polymerization under these conditions. The thermal polymerization of 1,2-dithiane was also studied in detail <2005POJ512, 2004MM3143>. 

Methyl Propargyl Sulfide from Sodium Methanethiolate and Propargyl Chloride CH3OH, h2o... 

Sodium hydroxide (0.60 mol) is dissolved in 40 ml of water and 150 ml of methanol is added. Methanethiol (0.60 mol) is liquified (—60 C) in a cold trap and 30 ml of cold (-20 C or lower temperature) methanol is added to the methanethiol. This cold mixture is added over -15 min to the solution of sodium hydroxide while keeping the temperature between 0 and 10 C. Subsequently 0.50 mol Of propargyl chloride (or bromide) is added dropwise over 20 min while keeping the temperature between 0 and 10 C. Salt separates immediately from the solution. After stirring for an additional half hour at -15 C, 500 ml of an aqueous solution of 10 g of KOH is added (to prevent stench due to hydrolysis of the excess of sodium methanethiolate). The mixture is extracted ten times with small portions (total amount - 500... 

Chlorinated 2H- pyrimido[l, 2-6 ]pyridazin-2-ones are known to undergo a variety of nucleophilic displacement reactions. Displacement of the chlorine atom in both the 4- and 7-positions of these compounds with methylamine and sodium methanethiolate is facile. Displacement of the chlorine atom in the 3-position does not occur. Therefore, 3,4,7-trichloro-2//-pyrimido[l,2-6]pyridazin-2-one (34) reacts with methanethiol in sodium methoxide to give 3-chloro-4,7-bis(methylthio)-2//-pyrimido[l,2-6]pyridazin-2-one (70) (71JOC3506). 

The replacement of only one fluorine in 2,6-difluoropyridinc by the benzylsulfanyl group proceeds quantitatively in dimethylformamide at 0 C using potassium tert-butoxide as base.10 In fluoropyrimidincs, fluorine in the 4-position is sufficiently reactive that it can be replaced by sodium methanethiolate in methanol at —20 C to give, c.g. 1 in almost quantitative yield further examples of the replacement of fluorine by methylsulfanyl are the formation of2and3. 1... 

The reactivity depends on the nature of the substituent in the 4-position,1415 with S02NH2 > S03NH4 > H, and also on the fluorine position, as 4-fluoro-2,1,3-bcnzoxadiazole is susceptible to fluoride elimination by sodium methanethiolate, in contrast to 5-fluoro-2,1,3-benzoxadi-azole.16... 

Fluoro-l, 3-benzothiazoIe reacts with sodium methanethiolate to give 2-(mclhylsulfanyl)-1,3-benzothiazole under very gentle conditions,17 as given for 4-(aminosuIfonyl)-7-fluoro-2,l, 3-benzoxadiazole (vide supra). 

Demethylthiocolchicine from 3-Demethylcolchicine. Sodium methanethiolate (800 mg) was added to a solution of 3-demethylcolchicine (600 mg) in water (6 ml). The reaction mixture was stirred at room temperature for 24 hr, diluted with 2% acetic acid (15 ml), and extracted with chloroform (3 times 100 ml). Drying (Na2SO,i) and evaporation of the combined chloroform extracts afforded 3-demethylthiocolchicine as a pale yellow powder (530 mg), which was recrystallized from acetone (400 mg, 67%) mp 310°C [a]D -259° (0.1, CHC13). This material was identical in every respect with the one prepared from colchicoside (/). 

In the synthesis of 2-[3-(methylsulfanyl)propyl]-lf/-indole 572, the key step was the alkylation of indolyllithium 570 with excess of l-bromo-3-chloropropane (Scheme 116) <200381191 >. Treatment of the indole 571 with sodium methanethiolate gave the target sulfide 572 in high yield. This compound was used in the synthesis of 5-methyl-2,3,4,5-tetrahydrothiopyrano[3,2- ]indole (see Section 3.02.4.8). 

An aqueous solution consisting of sodium methanethiolate (0.24 mol), 95% NaOH (0.15 mol) and water (0.15 mol) was added to 2-chloropyridine (0.20 mol) and tetrabutylammonium bromide (2.3 g) over 2 hours at 80-90°C. Thereafter, the mixture stirred 5 hours at 90-100°C. The two layers were separated and the product isolated in 95% yield. 

Quinazolinones 1 bearing a methoxy substituent in the benzene ring, readily obtained by cyclization of the appropriate precursors (cf. Section 6.3.1.1.1.), are transformed into the corresponding hydroxyquinazolinones 2 on treatment with hydrobromic acid, - hydriodic acid, aluminum trichloride,or boron tribromide. Similarly, quinazoline-2,4-diamines bearing a methoxy group at position 6 or 8 are demethylated with boron tribro-mide in dichloromethane, sodium methanethiolate in dimethylacetamide or by pyridini-um hydrochloride fusion at 200... 

Chloro-3-dichloromethylpyrazine with sodium methanethiolate has been claimed to give a mixture of products analogous to those obtained from its reaction with sodium methoxide (688). 2-Amino-5-chloromethyl-3-cyanopyrazine with... 

Iminothioethers have similarly been prepared from nitriles. 2-Amino-3-cyano-pyrazine with sodium methanethiolate (other alkanethiolates reached similarly) in ethanol gave 2-amino-3-(Cimino-C-methylthiomethyl)pyrazine (60) (792, 878, 1075) [which with guanidine hydrochloride and sodium methoxide in methanol gave 2-amino-3-(C-guanidino-C-iminomethyl)pyrazine (878)] 2-amino-5-chloro-3-cyanopyrazine with methanethiol and sodium hydroxide in methanol gave 2-amino-5-chloro-3-(C-imino-C-methylthiomethyl)pyrazine (877, 1218) [which with... 

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