Methylthio tetrahydrofuran

Physical Data bp 66-67 °C/21 mmHg 1.4868. Preparative Methods conveniently prepared in two steps in 46% yield from THF by light-initiated a-chlorination with sulfuryl chloride at — 30°C followed by reaction with meth-anethiol/triethylamine at —78 °C. Deprotonation with butyl-lithium gives 2-tetrahydrofuranyl(thiomethyl)lithium [98194-88-8].  

Thiol and Disulfide Synthesis. Reaction of 2-tetrahydrofu-ranyl(thiomethyl)lithium with tert-butyldimethylchlorosilane, followed by n-BuLi and a second equivalent of t-butyldimethyl-chlorosilane followed by hydrolysis of the adduct with sil-ver(I) nitrate or mercury(II) chloride followed hy hydrogen sulfide or hydrogen chloride gives bis(f-butyldimethylsilyl)-methanethiol (t-BuMe2Si)2CHSH 91%) (eq 1).  

5b7 Mi7y partially soluble in water soluble in DMF andCHsCN. 

Preparative Methods this reagent can be readily prepared from methyl thiocyanate and sodium azide in the presence of ammonium chloride in anhydrous DMF. Alternatively, it can be prepared by the reaction of methyl thiocyanate and sodium azide in water with zinc bromide as the catalyst.  

Handling, Storage, and Precaution this reagent should be handled with precaution. It may be irritating to the eyes, the respiratory system, and harmful to the skin. Avoid contact with strong heat and metal salts since tetrazoles may be explosive. It should he stored in the dark in a desiccator. 

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Zur Losung von 30 mg (0,011 mmol) 4-Brom-5-methoxycarbonyl-l-methyl-2-methylthio-imidazol in 5 ml Tetrahydrofuran gibt man bei 0° 10 mg feuchtes Raney-Nickel (W-2). Dann ruhrt man 30 min. bei 20°, filtriert das Nickelsulfid ab und dampft zur Trockcne ein Ausbeute 24 mg (93%) Schmp. 91 94°. 

D. trans-4-Hydroxy-2-hexenal. In a 500-ml., one-necked flask containing a Tcflon -coated magnetic stirring bar is placed 3.85 g. (0.02 mole) of l,3-bis(methylthio)-l-hexen-4-ol, 80 ml. of tetrahydrofuran (Note 11), and 6.00 g. (0.06 mole) of powdered calcium carbonate. The mixture is stirred, and a solution of 16.4 g. (0.06 mole) of mercuric chloride in 140 ml. of tetrahydrofuran and 40 ml. of water is added. The mixture is stirred and heated at 50-55° with a water bath for 15... 

Methyl-l-penten-3-one-l-ol 1 and glacial acetic acid in benzene was added to pyrrolidine to give 2-methyl-l-pen ten-1-[N-pyrrolidinyl]-3-one 2. Compound 2 when treated with oxalyl chloride and methanol was added, 3,5-dimethyl-2-methoxycarbonyl-4-pyrone 3 was produced. Treatment of compound 3 with sodium borohydride in methanol gives 3,5-dimethyl-2-hydroxymethyl-4-pyrone 4. Compound 4 was converted to 3,5-dimethyl-2-hydroxymethyl-4-pyridone 5 by heating compound 4 with aqueous ammonia in a sealed flask. Compound 5 was converted to 4-chloro-2-chloromethyl-3,5-dimethyl pyridine 6 by treatment with phosphorous oxychloride. Treatment of compound 6 with 5-methoxy-2-mer-captobenzimidazole in tetrahydrofuran gave 2-[2-(4-chloro-3,5-dimethyl pyridinyl)methylthio]-5-methoxy benzimidazole 7. When compound 7 was treated with potassium hydroxide in dimethyl sulfoxide containing methanol, 2-[2-(3,5-dimethyl-4-methoxypyridinyl)methylthio]-5-methoxy... 

A mixture of 6.63 g of 2-hydroxymethyl-3-methyl-4-(2,2,2-trifluoroethoxy) pyridine (30 mmol), 4.5 g of 2-mercaptobenzimidazol (30 mmol) and 8.67 g of triphenylphosphine (33 mmol) was dissolved in 100 ml of tetrahydrofuran, 5.75 g of diethyl azodicarboxylate (33 mmol) dissolved in 30 ml of tetrahydrofuran was added dropwise thereto at room temperature, and stirred for 1 hour. The reaction mixture was concentrated under a reduced pressure, the resulting residue was combined with 100 ml of ethylacetate, and extracted twice with 50 ml portions of 1 N HCI. The aqueous layer was then washed with 50 ml of diethylether neutralized with 1 N NaOH to adjust the pH to 7. The resulting precipitates were filtrated, washed with water, and dried, to obtain 10.06 g of 2-[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridyl]methylthio-lH-benzimidazole as a white solid (yield 95%), m.p.l42-144°C. 

Piperazine-2,5-dione treated with sodium hydride in A,A-dimethylacetamide and carbon disulfide followed by esterification with methyl iodide gave l-methylthio(thio-carbonyl)piperazine-2,5-dione (methyl 2,5-dioxopiperazine-l-dithiocarboxylate) and l,4-bis[methylthio(thiocarbonyl)]piperazine-2,5-dione (107), but when the reaction was carried out in dimethyl sulfoxide containing tetrahydrofuran it afforded (107) plus 3-[bis(methylthio)methylene]-l-methylthio(thiocarbonyl)piperazine-2,5-dione (108) (1630). 

Direct irradiation of 9-dimethylsulphonium fluorenylide (141) in acetonitrile or tetrahydrofuran yields primarily the Stevens rearrangement product 9-methyl-9-(methylthio)fluorene (142), and a 1,2-shift of a sulphonic acid group is thought to be involved in the photoisomerization of the sodium salt of metanilic acid (m-aminobenzenesulphonic acid). Photoinduced rearrangement of 4,5-(ethylenedithio)-1,3-dithiole-2-thione (143) to the... 

The ability of 1,3-dithiolium salts to add hydride ions has been widely studied. 2-Unsubstituted salts as well as 2-alkyl or 2-aryl, 2-amino, and 2-methylthio derivatives are easily reduced to give 1,3-dithioles in excellent yields (Eq. 38). Reducing agents are sodium hydrosulfide in ethanoF sodium borohydride in methanol, ethanol, or tetrahydrofuran - lithium aluminium hydride or deuter-ide in ether or sodium borodeuteride in acetonitrile. ... 

The use of 1,2-disubstituted hydrazine hydrochlorides with / -keto esters seems to work well under milder conditions. The condensation of 1,2-dimethyl- or 1,2-diethylhydrazine hydrochlorides 63a,b with methyl 2-(4-fluorophenyl)-3-[2-(methylthio)pyrimidin-4-yl]-3-oxopropanoate 62 required heating under reflux in ethanol to give pyrazol-3-ones 64a,b (05BMCL2285) (Scheme 15). The /i-keto ester 62 was synthesized by coupling methyl (4-fluorophenyl)acetate 60 with 2-(methylthio)pyrimi-dine-4-carboxaldehyde 61 in tetrahydrofuran with LDA at —78 °C, followed by chromium(VI) oxide oxidation. 

The interaction of sodium perthiocyanate (438) and suitable bifunctional dihalides readily produces polymers (444) which are claimed to be useful catalysts in the production of polyurethane foams. The use of l,4-di(chloro-methyl)benzene in ethanol, for example, gives 444 (R = p-CH2C6H4CH2, terminating in p-CH2C6H4CH2OEt, mol wt 2960) in 90% yield.354 5-Mercapto-3-methylthio-1,2,4-thiadiazole yields the tin-containing derivatives 445 (R = Bu, Ph, or cyclohexyl n = 1-3) on treatment with alkyltin halides in tetrahydrofuran.355... 

B. 4 -(Methylthio)-2,/ 6, Z"-teFpyridine. A 1-L, three-necked round-bottomed flask fitted with a mechanical stirrer and a gas inlet tube is flushed with nitrogen and charged with 500 ml of anhydrous tetrahydrofuran and... 

A solution of 1.0 g LAH in 25 mL tetrahydrofuran was cooled, under He, to 0 °C with an external ice bath. With good stirring there was added 0.6 mL 100% H2S04 dropwise, to minimize charring. This was followed by the addition of 1.1 g of 1-(4-ethyl-2-methoxy-5-methylthio)-2-nitropropene in a small amount of THF. After 10 min further stirring, it was brought up to room temperature and allowed to stand for several days. The excess hydride was destroyed by the... 

From these studies it may be concluded that boron is a borderline acceptor which becomes hard when surrounded by hard ligands, and it is rendered soft by soft substituents (e.g., H ). 3-(Methylthio)propylborane (7) is more stable than the borane-tetrahydrofuran complex (8) and it is distillable (33). The boron atom of the dihydroborepin (9) is internally coordinated by the amino nitrogen however, this chelation is removed by the addition of trityl fluoro-borate (34). This may indicate that the boron atom in the borinic esters (10) is harder, but not as hard as the trityl cation. 

Methyl dithiobutyrate added under Ng with stirring at -20° to 3 equivalents ethylmagnesium bromide in tetrahydrofuran, stirring continued 1 hr. at the same temp., then treated with water -> 1-ethylthio-l-methylthio-n-butane, Y 73%. F. e. s. L. Leger and M. Saquet, C. r. 279 (C), 695 (1974) Bl. 2975, 657. 

Ethyl N-[bis(methylthio)methylene]glycinate in dry tetrahydrofuran added drop-wise at -70° under Ng to K-t r/-butoxide in the same solvent, stirred 10 min., p-bromobenzyl bromide in tetrahydrofuran added, allowed to warm to room temp., stirred 15 min., recooled to -70°, allowed to react as above with more K-terf-butoxide and with ethyl iodide ethyl 2-[bis(methylthio)methylene]amino-2-(p-bromobenzyl)butyrate (Y 84%) dissolved in formic acid, stirred and treated at 0° with 30%-H202 and p-toluenesulfonic acid, kept 4 hrs. at 10° and 20 hrs. at 20° -> ethyl 2-ethyl-p-bromophenylalaninate (Y 90%). F. e. s. D. Hoppe, Ang. Ch. 87, 450 (1975) related synthesis and f. reactions with ethyl N-benzylidene-glycinate s. G. Stork, A.. Y. W. Leong and A. M. Touzin, J. Org. Chem. 41, 3491 (1976). 

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