Pyridine-2-acetamide

Furium. N[4-(5-Nitro-2-furanyl)-2-thia2olyl]acetamide, has demonstrated activity against baciUi and pathogenic enterobacteria (24). The product, prepared from thiourea and 2-bromo-l-(5-nitro-2-furanyl)ethanone followed by acetylation of the intermediate aminothia2ole with acetic anhydride in pyridine (25), is marketed in several countries for both human and veterinary use. 

Similar disproportionation reactions are catalyzed by organic catalysts, eg, adiponittile, pyridine, and dimethyl acetamide. Methods for the redistribution of methyUiydridosilane mixtures from the direct process have been developed to enhance the yield of dimethylchlorosilane (158). 

Sulfation by sulfamic acid has been used ia the preparation of detergents from dodecyl, oleyl, and other higher alcohols. It is also used ia sulfating phenols and phenol—ethylene oxide condensation products. Secondary alcohols react ia the presence of an amide catalyst, eg, acetamide or urea (24). Pyridine has also been used. Tertiary alcohols do not react. Reactions with phenols yield phenyl ammonium sulfates. These reactions iaclude those of naphthols, cresol, anisole, anethole, pyrocatechol, and hydroquinone. Ammonium aryl sulfates are formed as iatermediates and sulfonates are formed by subsequent rearrangement (25,26). 

A 6,6-dimethyl-6,7-dihydropyrido[l,2-c]quinazolinium salt was obtained from the reaction of 2-(2-aminophenyl)-pyridine and acetone <1997AJC109>. Reaction of 3-methyl-l,2,3,4-tetrahydroisoquinoline-l-acetamides 195 (R = H) with 36% aqueous CH20 gave 1,3,4,6,7,11 b-hcxahydro-2//-pyrirmido[6,1 - ]isoquinolin-2-oncs 153 and their 3-methyl derivatives <1997LA1165>. When the reaction was carried out in the presence of 37% aqueous NaOH, 3-hydroxymethyl derivatives 152 were obtained. Reactions with PhCHO were stereospecific affording only diastereomers 196 (Equation 41). 

These include hydrazine, dimethylsulfoxide (DMSO), formamide and some derivatives (N-methylformamide and dimethylformamide), acetamide and some derivatives, and pyridine N-oxide. Some salts such as potassium acetate also intercalate kaolinites. Once intercalated by one of these small molecules or salts, other molecules which normally do not directly intercalate kaolins can be introduced by replacement. Further, the exposure of the inner surfaces by intercalation gives one the opportunity to alter the interlayer bonding of the kaolin layers by chemical modification of the inner surfaces. 

A 30-mL flask containing 0.2 mL of TTX solution (250 MU) and 0.5 mL of 1.5 N NaOH is heated at 80-90 °C for 30 min to derive C -base from TTX (18, 25). After being cooled to room temperature, the reaction mixture is adjusted to pH 3-5 with 10% HCl and extracted 3 times with 2 mL of n-butanol. The combined extracts are evaporated to dryness under reduced pressure. The C -base in the residue is converted to the trimethylsilyl derivative in the presence of N,0-bis(trimethyl-silyl)acetamide, trimethylchlorosilane and pyridine (2 1 1). This derivative is then applied to GC-MS (Hitachi 063 gas chromatograph column (2 m x 3 mm I.D.), Chromosorb W coated with 3% OV-1, temperature 180-250 °C (5 °C/min) Hitachi RMU 6 MG mass spectrometer ionization voltage 70 eV, carrier gas helium). 

The earliest examples of such fluorine-18 labelling are 2- and 6-[ F]fluoronico-tinic acid diethylamide and 2- and 6-[ F]fluoronicotine (Fig. 5). All were obtained in up to 40-50% radiochemical yield from the corresponding 2- and 6-chloro-(or bromo-) pyridine derivatives and [ F]fluoride as its cesium salt, in melted acetamide or DMSO at about 200 °C for 30 min [226-229]. 

B. Kuhnast, B. Lagnel - de Bruin, F. Hinnen, B. Tavitian, F. Dolle, Design and synthesis of a new [ F]fluoropyridine-based haloacetamide reagent for the labeling of oligonucleotides 2-Bromo-N-[3-(2-[ F]fluoro-pyridin-3-yloxy)-propyl]-acetamide, Bio-conj. Chem. 15 (2004) 617-627. 

N,0-Bis(trimethylsilyl)acetamide (3) is an alternative trimethylsilylating reagent that has been found to trimethylsilylate L-ascorbic acid completely,139 and to react with tertiary hydroxyl groups in steroids.140,141 The latter observation is of interest, in view of the isolation from antibiotic substances of branched-chain carbohydrates possessing tertiary hydroxyl groups.142 Some authors have recommended that the highly reactive bis(trimethylsilyl)acetamide (3) be used in the absence of pyridine, in preference to a mixture of hexamethyldisilazane and chlorotrimethylsilane in this solvent.143 In the tri-... 

A wide variety of acidic compounds has been trimethylsilylated, and the preferred procedure is to treat the sodium, calcium, or barium salt, as a suspension in pyridine, with bis(trimethylsilyl)acetamide and chlorotrimethylsilane 100,163,164 this gives the trimethylsilyl ester of the O-trimethylsilyl derivative. Lead salts may be used,165 or the potassium salt may be used in methyl sulfoxide, the O-trimethylsilyl derivative becoming concentrated in the upper phase.166... 

Although this article is primarily concerned with gas-liquid chromatography of simple carbohydrates, it is worth noting that certain polysaccharides have been trimethylsilylated. Thus, chlorotrimethyl-silane in pyridine yielded fully trimethylsilylated amylose, cellulose, and pullulan, but failed with dextran and amylopectin.196 Cellulose, amylose, and polyvinyl alcohol have also been trimethylsilylated in molten N-(trimethylsilyl)acetamide.197 As examples of a new class of... 

Nitric acid. Sulfuric acid, N-Methylhydroxy acetamide Phosphorus oxytrichloride. Benzene, Neopentyl glycol. Pyridine, Petroleum ether. Ammonium fluoride Thiophosphorus trichloride. Benzene, Neopentyl glycol. Pyridine, Petroleum ether. Ammonium fluoride Nitric acid. Sulfuric acid. Glycerol, Magnesium sulfate Anhydrous hydrazine. Cyanogen bromide. Isopropyl alcohol. Sodium nitrite. Sodium bicarbonate. Copper nitrate trihydrate. Nitric acid. Diethyl ether... 

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