Ureas nitrophenyl

Phenyl(o-nitrophenyl)methyl, 345 Urea-Type Derivatives... 

Nitrophenyl urea [556-10-5] M 181.2, m 238 . Crystd from EtOH and hot water. 

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. 

C7H 4C1N 54777-54-7) see Clemastine 2-chloroethyl 4-nitrophenyl ether (C HgClN03 3383-72-0) see Dofetilide 7V-(2-chloroethyl)-N -(5-nitro-2-thiazolyl)urea (CgH7ClN403S 3311-98-6) see Niridazole 7V-(2-chloroethyl)piperidine... 

Scialdone MA, Shuey SW, Soper P, Hamuro Y, Bums DM. Phosgenated p-nitrophenyl(polystyrene)ketoxime or phoxime resin. A new resin for the solid-phase synthesis of ureas via thermolytic cleavage of oxime-carbamates. J Org Chem 1998 63 4802-4807. 

A recent study concerned the microwave-assisted parallel synthesis of di- and tri-substituted ureas utilizing dedicated 96-well plates in the CombiCHEM system [60], In a typical procedure, modification of the Marshall resin utilized was achieved by treatment with p-nitrophenyl chloroformate and N-methylmorpholine (NMM) in dichloromethane at low temperatures. The resulting resin was further modified by attaching various amines to obtain a set of polymer-bound carbamates (Scheme 7.48). 

There are many organic and inorganic materials available which exhibit significant non-linear optical properties. In the present context, however, we underline that ferrocene derivatives were the first organo-metallic materials observed possessing non-linear optical properties. In fact, in 1987 it was reported that ci s-ferrocenyl-2-(4-nitrophenyl)ethylene has a 62-fold greater efficiency than urea in generating the second harmonic, Scheme 13.71... 

The combinatorial library synthesis of a diverse set of trisubstituted ureas has been described [64]. The synthetic pathway involves the prehminary preparation of various nitrophenylcarbamates from commercially available nitrophenyl chlorofor-mate and a selection of amines allowing for wide scope in the divergence of the final urea products. In a further reaction of the nitrophenylcarbamates with a second amine, the urea was generated. Simultaneous addition of an electrophilic and basic scavenger resin removed all by-products, again allowing rapid isolation of the products in excellent yield and purity (Scheme 2.43). 

Brydon and Roberts- added hemolyzed blood to unhemolyzed plasma, analyzed the specimens for a variety of constituents and then compared the values with those in the unhemolyzed plasma (B28). The following procedures were considered unaffected by hemolysis (up to 1 g/100 ml hemoglobin) urea (diacetyl monoxime) carbon dioxide content (phe-nolphthalein complex) iron binding capacity cholesterol (ferric chloride) creatinine (alkaline picrate) uric acid (phosphotungstate reduction) alkaline phosphatase (4-nitrophenyl phosphate) 5 -nucleotidase (adenosine monophosphate-nickel) and tartrate-labile acid phosphatase (phenyl phosphate). In Table 2 are shown those assays where increases were observed. The hemolysis used in these studies was equivalent to that produced by the breakdown of about 15 X 10 erythrocytes. In the bromocresol green albumin method it has been reported that for every 100 mg of hemoglobin/100 ml serum, the apparent albumin concentration is increased by 100 mg/100 ml (D12). Hemolysis releases some amino acids, such as histidine, into the plasma (Alb). 

Recently, Scialdone and colleagues have employed phosgenated />-nitrophenyl(poly-styrene) ketoxime (Phoxime, 76) resin in the synthesis (via 77 and 78) of acyclic and heterocyclic amino-acid-derived ureas 79 too (Scheme 42). Resin 75 was first reacted with an amino acid and TMSCl in pyridine, and the resulting carbamate acid resin 77 was then coupled with an amine under standard carbodiimide protocol (HOBt/DIC in DMF) to obtain the carbamate amide resin 79. 

FIGURE 11. X-ray structure of (a) Af-chloro-At-methoxyurea (5) and (b) At-chloro-At-(2-methoxy-carbonyl)propyl-2-oxy-Af -(4-nitrophenyl)urea (6) with displacement eUipsoids shown at the 50% level. Bond lengths and angles are given in Table 1... 

In subsequent years, much evidence has been adduced to support this mechanism. Alkaline phosphatase and, by analogy, other serine enzymes, are directly phosphorylated on serine serine phosphate is not an artifact (Kennedy and Koshland, 1957). In the presence of nitrophenyl acetate, chymotrypsin is acetylated on serine, and the resulting acetylchymotrypsin has been isolated (Balls and Aldrich, 1955 Balls and Wood, 1956). Similarly, the action of p-nitrophenyl pivalate gave rise to pivaloyl chymotrypsin, which could be crystallized (Balls et al., 1957). Neurath and workers showed that acetylchymotrypsin is hydrolyzed at pH 5.5, but that it is reversibly denatured by 8 M urea the denatured derivative is inert to hydrolysis and even to hydroxylamine, whereas the renatured protein, obtained by... 

N,N-dimethyl-N (2-nitrophenyl)-urea 5 D1367 N,N -dimethyl-N-(2,4,6-trinitrophenyl)-urea 5 D1367... 

Moreover, high enantioselectivity has been reported for an MIP that was selective for Z-glutamate [33]. Here, changes in the UV-vis absorbance of the l-(4-styryl)-3-(3-nitrophenyl)urea monomer were monitored, as opposed to the previous studies where the intrinsic absorbance of the template was measured. The UV-vis spectroscopy titration of the functional monomer with different concentrations of the template in solution led to a bathochromic shift from 349 to 364 nm. The colour change of both the solution and the resulting bulk polymer upon addition of Z-glutamate was visible even to the naked eye, with a 1 1 monomer-to-template ratio demonstrated. 

A preparatively useful approach to the enantiomerically pure antihypertensive agent (R)-SQ 32,926 was disclosed by Atwal et al. (Scheme 4.13) [169]. In the first step, the 1,4-dihydropyrimidine intermediate 38 is acylated at N3 with 4-nitrophenyl chloroformate followed by hydrolysis with HC1 in THF to give DHPM 39. Treatment with (R)-a-methylbenzylamine provided a mixture of diastereomeric ureas from which the (R,R) isomer 40 was separated by crystallization. Cleavage with TFA provided (R)-SQ 32,926 in high enantiomeric purity. Similar strategies have been used to obtain a number of pharmacologically important DHPM derivatives in enantiomerically pure form [169, 186, 187]. 

Diphenylimidazole is nitrated by nitric and sulfuric acids in the presence of urea to give 96% of 4,5-bis(4-nitrophenyl)imidazole [90GEP(O)3835195], whereas amyl nitrite reacts with 4,5-diphenylimida-zole to give 2-nitro-4,5-diphenylimidazole (42). This reaction may be re-... 

Besides urea and thiourea, amide groups can also form effective chromogenic anion sensors. Jurczak and coworkers [14] have demonstrated the use of amide groups containing nitrophenyl-macrocycle 3 as a selective colori-... 

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