Pyridine urea

Amino-3-aroylthieno[2,3-f]pytidines have been synthesized for their potential to serve as allosteric enhancers at the adenosine Aj receptor <2006BML5530>. Thieno[3,2-f]pyridine derivatives have been found to be potent Lck inhibitors that are highly selective within the Src-family of tyrosine kinases <2007BML1167>. Thieno[3,2-f]pyridine urea compounds have been shown to be potent inhibitors of KDR kinase <2007BML1246>. Thieno[2,3-/ ]pyridine-... 

Keywords 2-hydroxybenzaldehyde, sulfide, nitrile, pyridine, urea-hydrogen peroxide complex, catechol, sulfoxide, sulfuric ester, amide, pyridine-/V-oxidc... 

Magnesium nitrate hexahydrate, Mg(N03)2-6H20, is prepared by dissolving magnesium oxide, hydroxide, or carbonate in nitric acid followed by evaporation and crystallization at room temperature. Magnesium nitrate is soluble in methanol and ethanol and also forms addition compounds with pyridine, urea, and aniline. 

Analytical screens are performed with both reverse-phase RP-HPLC and SFC isolation techniques. Analytical SFC should be screened first unless instrumentation availability or project background specifics dictate otherwise. Screening achiral column bonded phases varying in polarity and functionality against different mobile-phase solvent choices is effective for identifying analytical methods for the purpose of impurity isolation. There are currently many unique achiral SFC bonded phase column choices commercially available (2-ethyl pyridine, diethyl amino, dinitrophenyl, pyridine urea, diol, cyano, etc.). SFC column choice provides the most impact in manipulation of relative selectivity for individual... 

Urea - formaldehyde polymers. Formalin and urea (usually in the molecular proportions of 3 2) condense in the presence of ammonia, pyridine or hexamine to give urea - formaldehyde polymers, known commercially as Bedle or Plaskon, and are widely used as moulding powdens. It is believed that the intermediate products in the condensation are methylol-urea and dimethylol-urea ... 

Bis(carbamoyl) peroxides of the foUowiag structure were prepared by reaction of the corresponding carbamoyl chlorides and hydrogen peroxide—urea complex in the presence of pyridine (211). 

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). 

Diazophenols, ie, o-hydroxyaryldiazonium salts, couple to 1-naphthol in weaMy basic solution primarily in the para position, but as the hydroxyl ion concentration is increased, formation of the ortho isomer is favored and is frequentiy the sole product. Pyridine and pyridine derivatives, urea, and acetate, etc, used as buffers can also catalyze azo coupling reactions (28). l-amino-2-naphthol-4-sulfonic acid [116-63-2] (1,2,4-acid) and 1-naphthol yield the important Eriochrome Black A [3564-14-5] (18a, R = H) (Cl Mordant Black 3 Cl 14640) which is reportedly (20) a mixture of ortho and para isomers. 

CP can also be prepared by the reaction of cellulose with phosphoms oxychloride in pyridine (37) or ether in the presence of sodium hydroxide (38). For the most part these methods yield insoluble, cross-linked, CP with a low DS. A newer method based on reaction of cellulose with molten urea—H PO is claimed to give water soluble CP (39). The action of H PO and P2 5 cellulose in an alcohol diluent gives a stable, water-soluble CP with a high DS (>5% P) (40). These esters are dame resistant and have viscosities up to 6000 mPa-s(=cP) in 5 wt % solution. Cellulose dissolved in mixtures of DMF—N2O4 can be treated with PCl to give cellulose phosphite [37264-91-8] (41) containing 11.5% P and only 0.8% Cl. Cellulose phosphinate [67357-37-5] and cellulose phosphonate [37264-91 -8] h.a.ve been prepared (42). 

The simplest [3 + 3] reactions in the pyridine series involve reaction of o-chloropyridinecarboxylic acid derivatives with three-atom fragments such as urea, thiourea(s), amidines and guanidines, e.g. (240) (241). Examples are known mainly in... 

C h loro ethyl)-3-[(2-methyl-4-ami no-pyridin-5-yl)methyl] urea Nimustine... 

Urea (3.2 g, 53 mmol), (NH4)2Mo04 (0.126g, 0.6 mmol), and pyridine-2,3-dicarboxylic acid (l.Og, 6 mmol) were ground together until homogenous. The lnixlure was stirred in 1,2,4-trichlorohenzene (40 mL) for 1 h at 156-160=C. A ground mixture of cobalt(II) oxalate dihydrate (1.1 g, 6 mmol) and urea (2.5 g, 42 mmol) was slowly added under N2. The temperature was maintained at 205-210 C for 3.5 h. On completion, excess 1,2,4-trichlorobenzene was removed by distillation under reduced pressure. The crude product was washed with benzene (100 mL), crushed and washed successively with EtOH, warm H20, warm 5% aq NaOH, warm H20, warm 2.5% HC1, and warm H20, and dried at 80 C yield 0.882 g (45%). 

Similarly, copper(II) 1,8,15,22-tetraazaphthaIocyanine can be made from copper(II) chloride, pyridine-2,3-dicarboxylic acid, and urea in the presence of a catalytic amount of ammonium molybdate(VI), heated to 210DC for 4-5 hours, in a yield of 52%.459... 

Purex process, 6,940 Barium, pentakis(diacetamide)-stereochemistry, 1, 99 Barium alkoxides synthesis, 2,336 Barium complexes cryptands, 3,53 phthalocyanines, 2, 863 porphyrins, 2,820 pyridine oxide, 3,9 urea, 3,9... 

Calcium-binding proteins, 6, 564, 572, 596 intestinal, 6, 576 structure, 6, 573 Calcium carbonate calcium deposition as, 6, 597 Calcium complexes acetylacetone, 2, 372 amides, 2,164 amino acids, 3, 33 arsine oxides, 3, 9 biology, 6, 549 bipyridyl, 3, 13 crown ethers, 3, 39 dimethylphthalate, 3, 16 enzyme stabilization, 6, 549 hydrates, 3, 7 ionophores, 3, 66 malonic acid, 2, 444 peptides, 3, 33 phosphines, 3, 9 phthalocyanines, 2,863 porphyrins, 2, 820 proteins, 2, 770 pyridine oxide, 3,9 Schiff bases, 3, 29 urea, 3, 9... 

In the course of this study, the authors determined /Lvalues for dibenzyl, methyl phenyl, methyl p-nitrophenyl, di-p-tolyl, di-isopropyl and tetramethylene sulphoxides and for diethyl, dipropyl and dibutyl sulphites. The /Lscales are applied to the various reactions or the spectral measurements. The /Lscales have been divided into either family-dependent (FD) types, which means two or more compounds can share the same /Lscale, family-independent (FI) types. Consequently, a variety of /Lscales are now available for various families of the bases, including 29 aldehydes and ketones, 17 carboxylic amides and ureas, 14 carboxylic acids esters, 4 acyl halides, 5 nitriles, 10 ethers, 16 phosphine oxides, 12 sulphinyl compounds, 15 pyridines and pyrimidines, 16 sp3 hybridized amines and 10 alcohols. The enthalpies of formation of the hydrogen bond of 4-fluorophenol with both sulphoxides and phosphine oxides and related derivatives fit the empirical equation 18, where the standard deviation is y = 0.983. Several averaged scales are shown in Table 1588. 

Carbodiimides have been prepared by desulfurization of thioureas by metal oxides, by sodium hypochlorite,4 or by ethyl chloroformate in the presence of a tertiary amine by halogena-tion of ureas or thioureas followed by dehydrohalogenation of the N,N -disubstituted carbamic chloride 8 and by dehydration of disubstituted ureas using -toluenesulfonyl chloride and pyridine.7 The method described above is a modification of that of Campbell and Verbanc. ... 

The mechanism involves the initial formation of a substituted urea followed by ring closure to form the thiohydantoin. The amino acid is dissolved in 60% aqueous pyridine containing the phenylisothiocyanate... 

Salts of dithiocarbamic acid can be prepared by the addition of primary or secondary amines to carbon disulfide. This reaction is similar to 16-9. Hydrogen sulfide can be eliminated from the product, directly or indirectly, to give isothiocyanates (RNCS). Isothiocyanates can be obtained directly by the reaction of primary amines and CS2 in pyridine in the presence of DCC. ° In the presence of diphenyl phosphite and pyridine, primary amines add to CO2 and to CS2 to give, respectively, symmetrically substituted ureas and thioureas ... 

A variation of this process uses carbodiimides, which can be prepared by the dehydration of N,N -disubstituted ureas with various dehydrating agents, among which are TsCl in pyridine, POCI3, PCI5, P2O5—pyridine, TsCl (with phase-transfer... 

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