2- naphthyl 3-nitrophenyl

Hydrazotctrazolc. 0826 Lead 5.5 -azotctrazolidc. 1020 Mercury 5.5 -azotctrazolidc. 0980 Mercury(II) 5-nitrotetrazolide, 0981 2-Methyltetrazole, 0814 2-Methy 1-5 -viny ltetrazole, 1511 l-(2-Naphthyl)-3-(5-tetrazolyl)triazene, 3394 5-/V-Nitroaminotctrazolc. 0415 1 -(2-Nitrophenyl)-5-phenyltetrazole, 3 602 5-Nitro-2-picryltetrazole, 2638 5-Nitrotetrazole, 0387... 

A few acetates of phenols have been used extensively as probes to investigate esterases, e.g., phenyl acetate (7.15), 4-nitrophenyl acetate (7.16), a-naphthyl acetate (7.17) and 7-acetoxy-4-mc(hyl-27/-[l bcnzopyran-2-onc (4-methylumbelliferyl acetate, 7.18). Such substrates are easy to handle and their phenolic metabolite is readily analyzed, allowing convenient monitoring of the reaction. 

Series of homologous esters have been investigated to try to establish structure-metabolism relationships, however partial and limited the latter may be. This aspect will be discussed again in the context of prodrugs (Chapt. 8). Here, we mention a few representative studies in which model substrates were used. Table 7.2 documents the substrate specificity of a rabbit liver carboxylesterase (ES-1A) toward homologous series of methyl, 4-nitrophenyl, a-naphthyl, /1-naphthyl, and 4-methylumbelliferyl esters [41]. In... 

Nitiophenyl 2, 2-nitrophenyl 3, 4-benzoylphenyl 4, 9-anthracenyl 5, 1-anthracenyl 6, 2-anthracenyl 7, 4-(2-(4-pyridyl)vinyl)phenyl 8, 3-acetylphenyl 9, 4-quinolyl 10, 4-acetylphenyl II, 2-quinolyl 12, 4-cyanophenyl 13, 1-naphthyl 14, 2-naphthyl. 

IsopropyI-4-nitrophenyl 2, 4-nitrophenyl 3, 2-methyl-3-nitrophenyl 4, 2-methyl-4-nitrophenyl 5, 3-fluorenyl 6, 1-fluorenyl 7, 2,6-dimethyl-4-nitrophenyl 8, 3-benzoyl-phenyl 9,4-benzoylphenyl 10,9-anthracenyl 11, 3-acetylphenyl 12,4-acetylphenyl 13, 1-naphthyl. 

Abbreviations Ahx, (V)-2-aminohexanoyl Nap, naphthyl (a- or p- not specified) / -NOiPh, >ara-nitrophenyl /i-CFsPh, /)ara-(trifluoromethyl)phenyl. Undefined mixture of CHC was used. 

The late discovery of acetyl xylan and feruloyl esterases has been partly due to the lack of suitable substrates. Xylans are often isolated by alkaline extraction, in which ester groups are saponified. Treatment of plant materials under mildly acidic conditions, as in steaming or aqueous-phase thermomechanical treatment, leaves most of the ester groups intact. These methods, however, partly hydrolyze xylan to shorter fragments (63,69). Polymeric acetylated xylan can be isolated from delignified materials by dimethyl sulfoxide extraction (70). The choice of substrate is especially important in studies of esterases for deacetylation of xylans. The use of small chromophoric substrates (p-nitrophenyl acetate, a-naphthyl acetate, and methylumbelliferyl acetate) analogously to the assays of disaccharidases may lead to the monitoring of esterases unable to deacetylate xylan (33, 63, 64). 

This procedure illustrates the best way to prepare aryl isocyanides. It is quite general, having been used by Ugi and Meyr e to make the following isocyanides from the corresponding form-amides phenyl (56%), />-tolyl (66%), 2,6-dimethylphenyl (88%), mesityl (80%), o-chlorophenyl (43%), -chlorophenyl (54%), 2-chloro-6-methylphenyl (87%), -methoxyphenyl (64%), p-di-ethylaminophenyl (75%), -nitrophenyl (41%), and 2-naphthyl (50%). Aliphatic isonitriles are generally best prepared by a simpler procedure involving the action of phosphorus oxychloride on an N-alkylformamide in the presence of pyridine.7... 

The aryl aldofuranosides show a greater lability to alkali than the alkyl aldofuranosides. Phenyl 0-n-xylofuranoside is very labile to alkali.82 Treatment of 2-naphthyl 0-D-glucofuranosidurono-6,3-lactone with dilute alkali opens the lactone ring, and rapid hydrolysis occurs.40 Ishidate and Matsui81 noted that p-nitrophenyl 0-D-glucofuranosidur ono-6,3-lactone is most sensitive to alkali, the amide next, find then the pyranoid derivatives toward acids, the relative sensitivities of the lactone and the amide are reversed. 

At biphenyl, naphthyl, 3,4-dichlorophenyl, 4-nitrophenyl 3-pbenoxyphenyl, 2-benzothiophenyl, 4-phenoxathiinyl R - CHj, C2H3... 

In practice it is often more convenient to measure the release of a phenol from an aryl phosphomonoester. Standard serum phosphatase methods employ phenyl phosphate (188), p-nitrophenyl phosphate (189), phenolphthalein monophosphate (140), or thymolphthalein monophosphate (141) where the phenol released can be determined spectrophoto-metrically [only the Bodansky method (13) uses a Pi determination]. A number of fluorogenic substrates have been used for phosphatase studies, e.g., jS-naphthyl phosphate (30, 148), 4-methylumbelliferyl phosphate (143), and 3-O-methylfluorescein phosphate (144) The main advantage here is the much greater sensitivity of fluorescence as compared with spectrophotometric assays as little as 1 pmole of 4-methyl-umbelliferone can be detected in continuous assay. 

Most investigators utilize p-nitrophenyl or a-naphthyl phosphate as substrate. The determination of serum prostatic acid phosphatase was developed by Fishman and Lemer (34) based on the d-(+)-tartrate inhibition of prostatic enzyme discussed below. Babson et al. (35, 36) demonstrated that a-naphthyl phosphate was much more easily split by prostatic than red cell phosphatase. Table V (35) shows the results obtained when prostatic or red cell phosphatase was added to human serum which had been incubated at pH 8.6 for 1 hr at 37° to destroy all endogeneous phosphatase activity. The table shows the superiority of a-naphthyl phosphate as substrate. 

Photooxidation of parathion also occurred on leaf surfaces (18), together with isomerization and other reactions. Fenitro-thion (j),O-dimethyl 0-3-methyl-4-nitrophenyl phosphorothionate) and other phosphorothionate insecticides behaved similarly (19). Some pesticides do not require external reagents for photodegradation on surfaces carbamate insecticides such as carbaryl (1-naphthyl li-methylcarbamate), aminocarb (4-dimethylamino-3-methylphenyl li-methylcarbamate), and mexacarbate (4-dimethylamino-... 

Detailed proton NMR spectroscopic data on a variety of fused and spiro thietane and thiete derivatives was tabulated in the corresponding sections of CHEC(1984) and CHEC-II(1996). Therefore, only limited, newer information is presented here. A series of iV-(4-methoxyphenyl), iV-(l -naphthyl), iV-benzyl, and iV-(4-nitrophenyl)-,/V-(thietan-3-yl)benzene- or methanesulfonamides 13 as well as the analogous iV-aryl-iV-(thietan-3-yl)-2-nitroben-zenesulfonamides 14, 3-arylaminothietanes 15, iV-(4-aryl)-iV-(l-oxothietan-3-yl)-2-nitrobenzenesulfonamides 16, iV-(l,l-dioxothietan-3-yl)-Ar-(aryl)-2-nitrobenzenesulfonamides 17, 3-(4-arylamino)thietane 1,1-dioxides 18, and iV-(4-aryl)-iV-(thietan-2-yl)benzamides 19 were identified on the basis of their H NMR spectra <2005RJ01023>. 

The O-dealkylation of organophosphorus triesters differs from the above reactions in that it involves the dealkylation of an ester rather than an ether. The reaction was first described for the insecticide chlorfenvinphos (Figure 10.2B), but is now known to occur with a wide variety of vinyl, phenyl, phenylvinyl, and naphthyl phosphates and the thionophosphate triesters. At least one phosphonate, O-ethyl O-p-nitrophenyl phenylphosphonate (EPNO), is also metabolized by this mechanism. 

The heat of dissociation is further lowered by replacing the phenyl groups wholly or partially by diphenyl and naphthyl groups, with still more configurations. Hexa j -nitrophenyl-ethane is also wholly dissociated. In this case configurations such as the following occur ... 

The 0,0-diethyl-o-p-nitrophenyl phosphorothioate (parathion) was obtained from the American Cyanamid Co., and the 1-naphthyl-N-methyl-carbamate (Sevin) was obtained from the R. A. Taft Sanitary Engineering Center, U. S. Public Health Service. The Dow Chemical Co. provided... 

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