Methyl 5-thio synthesis

Indole, 4,5,6,7-tetrahydro-4,7-dioxo-structure, 4, 303 Indole, tetrahydro-3-methyl-synthesis, 4, 109 Indole, 2-(2-thienyl)-nitration, 4, 211 Indole, 3-thio-synthesis, 4, 368 Indole, 2-thioalkyl-synthesis, 4, 152 Indole, 3-thiocyano-synthesis, 4, 368 Indole, 1-tosyloxy-rearrangement, 4, 302 Indole, 1,2,3-trialkyl-Mannich reactions, 4, 228 Indole, 3-(tricyanovinyl)-nucleophilic addition reactions, 4, 281 reactions... 

Uracil, 6-dimethoxymethyl-3-methyl-2-thio-synthesis, 3, 113 Uracil, 1,3-dimethyl-dimers, 3, 74 Uracil, 3,6-dimethyl-synthesis, 3, 106, 110 Uracil, 5-fluoro-... 

Uracil, 5-methoxy-6-methoxymethyl-2-thio-synthesis, 3, 134 Uracil, 1-methyl-aminolysis, 3, 91 synthesis, 3, 110 Uracil, l-methyl-5,6-dihydro-synthesis, 3, 110 Uracil, 6-methyl-3-phenyl-synthesis, 3, 110 Uracil, 3-methyi-2-thio-synthesis, 3, 112 Uracil, 6-methyl-2-thio-oxidation, 3, 94 Uracil, 5-nitro-... 

Uric acid, 9-methyl-2,8-dithio-, 5, 590 Uric acid, 9-phenyl-synthesis, 5, 577 Uric acid, 8-thio-synthesis, 5, 577, 582 Uric acid, 1,3,7-trimethyl-ethylation, 5, 534 methylation, 5, 535 Uric acid, 1,7,9-trimethyl-methylation, 5, 535 Uridine... 

Xanthine, 9-methyl-8-methylthio-2-thio-synthesis, S, 590 Xanthine, 7-methyl-8-phenyl-synthesis, S, 588 Xanthine, 7-methyl-2-thio-synthesis, S, 590 Xanthine, 9-methyl-2-thio-synthesis, 5, 590 Xanthine, 8-methylthio-2-thio-synthesis, S, 590... 

Fry et al. prepared quaternary salts from 4-methyl- and 4-methyl-thio-quinazoline and found that the same cyanine dyes were obtained by suitable reactions of either salt. An unambiguous synthesis of the 4-methylthio salt (69) from l-methylquinazoline-4-thione (70) proved that both of the salts carried groups on N-1. 

Shortly after the above work appeared, Bolliger and Prins90 reported a similar synthesis leading to a 3- rather than a 2-desoxy derivative. Methyl 2,3-anhydro-4,6-benzylidene-a-D-mannoside (LXIV), upon treatment with sodium thiomethoxide, was converted into methyl 3-methyl-thio-4,6-benzylidene-a-D-altroside (LXV) which, after desulfurization and rebenzylidenation, gave methyl 3-desoxy-4,6-benzylidene-a-D-man-noside (LXVI). Methylation of LXV with methyl iodide and silver oxide followed by desulfurization gave methyl 2-methyl-3-desoxy-4,6-benzylidene-a-D-mannoside in poor yield. 

Nizatidine Nizatidine is N-[2-[[[2-[(dimethylamino)methyl]-4-thiazolyl]methyl] thio] ethyl]-2-nitro-l,l-ethenediamine (16.2.15). According to its chemical structure, nizatidine is somewhat of a hybrid structure of ranitidine and famotidine, in which a side chain of ranitidine and carrying heterocycle, 2-aminothiazol, are used. Likewise, its synthesis also is a specific combination of pathways used for making both prototype drugs. 2-(Dimethyl-aminomethyl)-4-hydroxymethylthiazol serves as the initial compound, from which the desired nizatidine (16.2.15) is synthesized by subsequent reaction with 2-mercaptoethy-lamine hydrochloride and then with iV-methyl-l-methythio-2-nitroethenamine [71,72]. 

The synthesis of isomeric l,2,3,4-tetrakis(methyl-thio)hexafluoro-n-butane was finally achieved by photoassisted sonication, after the numerous attempts through the various methods had failed. A successful method described here consists of reacting trans-1,4-bis(methylth1o)hexafluoro-2-bu-tene in an excess of methyl disulfide with an added appropriate gas (hexafluoropropane) to increase and control the pressure in the reaction vessel. The heterogeneous mixture was then subjected to the combined photolysis and sonication at 50°C. The iaFNMR and mass spectral data of the product and the by-product l,2,4-tris(methylth1o)-3-H-hexafluo-ro-n-butane were presented. 

Cotton etal. [14] described an asymmetric synthesis of esomeprazole. Esomeprazole, the (S)-enantiomer of omeprazole, was synthesized via asymmetric oxidation of prochiral sulfide 5-methoxy-2-[[(4-methoxy-3,5-dimethyl pyridin-2-yl)methyl]thio]-lH-benzimidazole 1. The asymmetric oxidation was achieved by titanium-mediated oxidation with cumene hydroperoxide in the presence of (S,S)-diethyl tartarate (DET). The enan-tioselectivity was provided by preparing the titanium complex in the presence of sulfide 1 at an elevated temperature and/or during a prolonged preparation time and by performing the oxidation of sulfide 1 in the presence of amine. An enantioselectivity of 94% ee was obtained using this method. 

The route of synthesis of pantoprazole sodium, as described in US patent 4758579 (1988), is as follows. 2-chloromethyl-3,4 dimethoxypyridinium hydrochloride(I) is condensed with 5-difluoromethoxy-2-mercapto-benzimidazole(H) in ethanolic sodium hydroxide solution to yield 5-(difluoromethoxy)-2-(((3,4-dimethoxypyrolidine-2-yl) methyl) thio)-l/7-benzimidazole)(III). This compound is oxidized during reaction with m-chloroperbenzoic acid in methylene chloride, yielding pantoprazole base (IV). Further reaction with aqueous caustic soda solution gives pantoprazole sodium, which is then purified by crystallization from methanol. The various steps of this synthesis are illustrated in Scheme 1. 

An alternate route of preparation for pantoprazole has been reported by Pan Li et al [4], The compound was synthesized by refluxing 5-substituted phenylenediamine (I) with a pyridine derivative (II) in toluene to produce 5-(difluoromethoxy)-2-(((3,4-dimethoxypyridine-2-yl)methyl)thio)-1 /f-benimidazole(III). This reaction is followed by oxidation with m-chloroperbenzoic acid in chloroform to produce pantoprazole. The route of this synthesis is shown in Scheme 2. 

More recently, Wolfrom and Foster found that the d and l enantio-morphs of methyl 3,4-0-isopropylidene-2-0-[(methylthio)thiocarbonyl]-/3-arabinop3Tanoside rearrange, on pyrolysis, to the appropriate 2-methyl-thio)carbonyl] esters. The reductive desulfurization of methyl 3,4-0-isopropylidene-2- S - [(methylthio)carbonylj - 2 - thio -/3 - d - arabinopyranoside (LXVIII) with Raney nickel, to afford a low yield of methyl 2-deoxy-3,4-0-isopropylidene-/3-D-erj/intramolecular rearrangement to LXVIII, and the relationship of the transformation to the Chugaev reaction was discussed. 

Bos and coworkers have developed several applications of alkyne-ketone photoadditions to organic synthesis. 2 Irradiation of a solution of acetone and 1-methylthio-l-propyne gives as a major product the cycloadduct (67) this results from selective oxetane formation due to radical stabilization by the methyl-thio group, followed by electrocyclic ring opening. Similarly, photoreaction of benzil and 1-t-butylthio-1-propyne gave the adduct (68) in 45% yield, which was transformed in 90% yield to the furan (69). 

Indok synthesis. Gassman and van Bergen have used a modification of the above-mentioned procedure for synthesis of 2-substituted indoles from anilines. The aniline IS treated as above with a chlorinating reagent at — 65° and then an equivalent of methyl-thio-2-propanone at the same temperature. An equivalent of a base (usually triethyl-amine) is added. Workup affords the indole derivative (2) in 60-70% yield. The thio-methyl group is removed with Raney nickel (>70% yield). The keto sulfide can be varied thus nse of methyl phenacyl sulfide [CH3SCH2C(=0)C5H5]4 in the synthesis leads to 2-phenylindoles. 

Stereocontrolled lincomycin was synthesized from methyl - D galactopyranoside, I, of methyl thio -lincosa - minide, II, using the direct synthesis precursor to lincomycin (5). The off - pyranose stereocenters C - 6 and C - 7 were controlled by an intramolecular nitrogen delivery reaction using epoxy alcohol. 

Uracil, 6-dimethoxymethyl-3-methyl-2-thio-synthesis, 3, 113 Uracil, 1,3-dimethyl-dimers, 3, 74 Uracil, 3,6-dimethyl-synthesis, 3, 106, 110 Uracil, 5-fluoro-as anticancer drug, I, 263 antineoplastic activity, 3, 152 as pharmaceutical, I, 159 reactions, 2, 59 synthesis, 3, 70 Uracil, 6-fluoro-hydrolysis, 3, 101 Uracil, 5-hydroxy-1,3-dimethyl-synthesis, 3, 133 Uracil, hydroxymethyl-oxidation, 3, 91... 

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