Dimethylsulfate

The nitro group increases the acidity of the hydrogen born by the exocyclic nitrogen, and alkylation of 2-nitraminothiazole with diazomethane is possible (87), The formed 2-(A"-methylnitramino)-thiazole also may be obtained from the reaction of 2-nitraminothiazole with dimethylsulfate in basic medium (194). 

Alkylation of A-4-thiazoline-2-one may yield O-R or N-R derivatives according to experimental conditions. With diazomethane in ethanol O-raethylation takes place (29. 36. 214). N-Methylation is reported when a basic solution of A-4-thiazoline-2-one reacts with methyl iodide or dimethylsulfate (21, 29, 215, 216), Reaction of l-chloro-2-dimethyl-aminoethane with the sodium salt of 4 R-A-4-thiazoline-2-one (91) in alcohol, first claimed to yield the aminoalkylether (217, 218), was shown after infrared investigation to give the N-substituted derivative (92) (107), even when R Ph (Scheme 45). More probably the site of reaction in... 

Polyquatemium-11 is the copolymer of A/-vinylpyrrohdinone and dimethyl-arninoethyl methacylate quatemized with dimethylsulfate (20). It is used widely but provides Htde hold to the hair. Its primary advantage is its abiUty to improve the ease of wet combing and control static while giving a light set hold. 

Electrophilic substitution at ring nitrogen atoms has been limited to protonation and iV-alkylation of the anion derived from a pyrido-pyrimidinone.i - Thus, the sodium salt of pyrido-[2,3-d]pyrimidine-2,4-(l//,3ir)-dione and dimethylsulfate yield the 1,3-dimethy] derivative (176). 

Methylation using dimethylsulfate in alkaline media of acid 172 led to the corresponding 2-methyl-2//derivative (89FA619). 

Isopropyl-4(or 5-nitroimidazole) (31 g = 0.2 mol), dioxane (70 g) and dimethylsulfate (28 g = 0.22 mol) were heated on a steam bath under reflux for 45 minutes. The solvent was removed in vacuo on a steam bath, the residue dissolved in 20 ml of water and the product precipitated by the gradual addition of 80 g of 25% sodium hydroxide solution at 0°C. A small additional amount was obtained by extraction of the mother liquor with methylene chloride. The product melted at 60°C. 

Kondo maintained his interest in this area, and with his collaborators [62] he recently made detailed investigations on the polymerization and preparation of methyl-4-vinylphenyl-sulfonium bis-(methoxycarbonyl) meth-ylide (Scheme 27) as a new kind of stable vinyl monomer containing the sulfonium ylide structure. It was prepared by heating a solution of 4-methylthiostyrene, dimethyl-diazomalonate, and /-butyl catechol in chlorobenzene at 90°C for 10 h in the presence of anhydride cupric sulfate, and Scheme 27 was polymerized by using a, a -azobisi-sobutyronitrile (AIBN) as the initiator and dimethylsulf-oxide as the solvent at 60°C. The structure of the polymer was confirmed by IR and NMR spectra and elemental analysis. In addition, this monomeric ylide was copolymerized with vinyl monomers such as methyl methacrylate (MMA) and styrene. 

Die Reduktion geminaler Dibrom-cyclopropane mit Chrom(II)-acetat in Dimethylsulf-oxid fiihrt (in Abhangigkeit von Zeit und Temperatur) zu wechselnden Mengen an Brom-cyclopropanen. Aus 2,2-Dibrom-1,1-diphenyl-cyclopropan entsteht dagegen ausschlieB-lich 1,1 -Diphenyl-allen (s. S.517), in waBr. Dimethylformamid entstehen zusatzlich Aeetoxy-Derivate4 ... 

The rigid, planar pyridine analog 111 was isolated in low yield by first hydrolyzing the known (67) pyridine diethyl phosphonate 109 to the corresponding free acid 110 followed by permanganate oxidation (2). An alternative synthesis of 111 has recently been reported (68). Alkylation of pyridine-2-carboxylate -oxide with dimethylsulfate and subsequent reaction with the sodium salt of diethyl phosphite gave the triester 112, which was readily converted to 111. 

Blood Digested with H2SO4 dimethylsulfate at 60°C for 4 hours headspace gas injected into GC GC/ECD (trichloroethylene, trichloro-ethanol, and trichloroacetic acid) 3 ppb (trichloroethylene) 60 ppb (trichloro-ethanol) 30 ppb trichloroacetic acid) NR Monster and Boersma 1975... 

The key intermediate 2-thioxo-3-phenylquinazohn-4(3H)-one was prepared by adding carbon disulfide and sodium hydroxide solution simultaneously to a vigorously stirred solution of aniline 7 in dimethylsulfoxide over 30 min stirring was then continued for an additional 30 min. Dimethylsulfate was added to the reaction mixture whilst stirring at 5-10°C after which it was stirred for another 2 h and then poured into ice water to obtain a soHd dithiocarbamic acid methylester 6. The compoimd 6 and methylanthranilate 5 when refluxed in ethanol for 18 h yielded the desired 2-thioxo-3-substituted quinazolin-4(3H)-one 4. The product obtained was cycUc and not an open chain thiourea 5a. It was confirmed by its value, high melting point, and its... 

The 2-methylthio-3-substituted quinazolin-4(3H)-one 3 was obtained by dissolving 4 in 2% alcoholic sodium hydroxide solution and methylating with dimethylsulfate whilst stirring at room temperature (yield 88%, m.p 124-126 C). The IR spectrum of 3 showed the disappearance of the amino (NH) and thioxo (CS) stretching signals of the starting materials. It showed a peak for carbonyl (CO) stretching at 1680 cm The NMR spectriun of com-... 

Standard alkylating and cross-linking agents such as dimethylsulfate or TV-mustards, respectively, have only one opportunity to partition between various nucleophiles since their reactions are irreversible. In contrast, QMs have the potential to partition between nucleophiles multiple times as long as the resulting adducts are formed reversibly. Continual capture and release of QMs consequently can extend their effective lifetime almost indefinitely and is ultimately limited by only the competitiveness of possible irreversible reactions. For DNA, the strongest nucleophiles act reversibly so terminal quenching remains an infrequent event. 

Amino-squaraines 39 (Z1 = O, Z2 = R1R2) are synthesized by etherification of the oxo-squaraine oxygen using dimethylsulfate or methyl triflate followed by substitution of the methoxy group with amines [52] (Fig. 10). 

In a typical experiment a portion of the 5 -labeled single-stranded DNA is reacted with dimethylsulfate under conditions where many but not all of the purine bases react. This reagent alkylates the N7 position... 

In addition to pure water, we extended our investigation on solvated Li+ to NH3 (90), NH3-H20 mixtures (91), dimethylsulf-oxide (DMSO) (92), DMS0-H20 mixtures (92), HCN and CH3CN, and their mixtures with water (93). For NH3 as a water-like solvent, all published X-ray structures are tetrahedrally coordinated, [Li(NH3)4] + (94-97). Therefore, we expect to have [Li(NH3)4]+ in solution. The validity of this assumption is also supported by the exchange mechanism. In the case of DMSO, a variety of theoretical and experimental studies on liquid DMSO (98-104), DMSO-water mixtures (105-110), DMSO-non-aqueous... 

Ester formation by dimethylsulfate or diazomethane is not satisfactory because the microgels become insoluble when the reaction proceeds to higher conversions. With diazomethane part of the unsaturated groups is involved in a side reaction of a 1,3-dipolar cycloaddition [132]. A more efficient method for ester formation of microgels is the reaction with 0-alkyl-N,N -bisisopropyl isoureas of the alcohols. The alkyl ureas are easily separated from solutions in methanol [294-296]. The esterified microgels were isolated by precipitation and freeze-drying. Depending on the alcohol used for ester formation, the yields of... 

Convert 3,5-dihydroxyacetophenone (5-acetyl resorcinol) to 3,5-dimethoxyacetophenone(I) in the usual way with dimethylsulfate. 

Convert benzoic acid to 3,5-dihydroxybenzoic acid (alpha-resorcyclic acid) (I). 50 g (I), 134 g dimethylsulfate, 60 g NaOH, 300 ml water add 35 g NaOH and reflux to obtain about 50 g 3,5-dimethoxybenzoic acid (II) which is converted to dimethoxybenzoyl chloride (HI) with PCI5. Extract the (HI) with ether and filter. Saturate the ether with NH3 at 0° C and filter. Wash with ether and water and reciystallize from hot water to get 3,5-dimethoxy-benzamide (IV). To a solution of 1 M of n-hexyl bromide (or 1,2-dimethylheptyl bromide, etc.) add 24.3 g Mg in 200 ml ether to... 

B (Alternative) 0.05 M (II), 0.76 ml glacial acetic acid in 75 ml tetrahydrofuran (dry) are added slowly with stirring and cooling over one-half hour to a solution of 25.2 ml dimethylsulfate and 0.76 ml glacial acetic acid in 30 ml dry tetrahydrofuran. After two hours, filter and wash the precipitate with ether. Dissolve precipitate in 10% aqueous solution of KCN and heat one hour at 70°. Filter, wash precipitate with water and dry to get (III). 

Dissolve the OH-indole in ethanol (0.14 M in 50 ml) and add 28 ml dimethylsulfate and 1.2 g Na hydrosulfite. Add slowly with stirring and cooling (under N2 if possible) 12 g NaOH dissolved in 26 ml water (keep temperature at 20-25°). Heat to 70° for one-half hour, cool and dilute with an equal volume water. Extract the yellow oil into ether-benzene and dry, filter, and evaporate in vacuum to get the methoxy-indole. 

The Brellochs reaction represents a significant breakthrough in monocarbaborane chemistry, the exploration of which was previously limited by multistep routes. For example, the important carborane anion CBnFI12 can now be made in two steps with an overall yield of 66%.88 Its synthesis previously required three steps involving undesirable compounds such as hydrogen cyanide, dimethylsulfate, and trialkylamine. (COMC (1982) 5.4.2.6.2) The arachno-cztbotznc... 

Dimethoxybenzaldehyde. (This can be purchased for a modest fee from chemical supply houses. If you prefer to use the "make your own" method of procurement see the procurement chapter, then follow the instructions below.) Aust. J. Chem. 21, 2979 (1968). Make a mixture of 50 g 3,5-dihydroxybenzoic acid, 200 ml dimethylsulfate, 250 g K2CO3, in one liter of acetone, and reflux for 4 hours. Distill the acetone off and extract the residue with 1 liter of ether. Wash the extracts with two 100 ml portions of coned ammonium hydroxide, two 100 ml portions of... 

Buy 3,5-dimethoxybenzoic acid or make like this. 3,5-dihydroxybenzoic acid is mixed with 134 g of dimethylsulfate, 60 g of sodium hydroxide, 300 ml and 35 g more sodium hydroxide, then reflux. This 3,5-dimethoxybenzoic acid is converted to 3,5-dimethoxybenzoyl chloride by reacting with PCI5, which is extracted with portions of ether and filter. Saturate the ether with ammonia, after cooling the ether to 0°, and filter. Wash the solids with cold ether, then water, and recrystallize from hot water to get 3,5-dimethoxybenzamide. 

Diazepam From a chemical point of view, diazepam, 7-chloro-l,3-dihydro-l-methyl-5-phenyl-2H-l,4-benzodiazepin-2-one (5.1.2), is the most simple of all of the examined derivatives of l,4-benzodiazepin-2-ones. Various ways for the synthesis of diazepam from 2-amino-5-chlorobenzophenone have been proposed. The first two ways consist of the direct cyclocondensation of 2-amino-5-chlorobenzophenone or 2-methylamino-5-chlorobenzophenone with the ethyl ester of glycine hydrochloride. The amide nitrogen atom of the obtained 7-chloro-l,3-dihydro-5-phenyl-2H-l,4-benzodiazepin-2-one (5.1.1), is methylated by dimethylsulfate, which leads to the formation of diazepam (5.1.2). 

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