Chlorophenyl esters

Treatment of an intemucleotide 4-chlorophenyl ester with CsF and an alcohol (MeOH, EtOH, neopentylOH) results in transesterification. 

The Helferich-Wedemeyer procedure may give mixtures of the anomers, depending on the nature of the aglycon. For example, condensation of bromide 128 with N-(benzyloxycarbonyl)-L-threonine penta-chlorophenyl ester (171) gave both N-(benzyloxycarbonyl)-3-0-(2,3,4,6-tetra-O-acetyl-a- and -/J-D-glucopyranosyl)-L-threonine pen-tachlorophenyl ester135 (172 and 173, respectively), but only the fi-D... 

Similar phosphitylation and subsequent conversion to a dinucleotide has been carried out using the methyl- or m-chlorophenyl esters of a phosphorous acid bisazo-lide.[101H103]... 

If CDI is employed as imidazolide, methyl 2,4,6-trihydroxybenzoate is obtained in 47% yield. Propionyl-1,2,4-triazole behaves in the same way as the imidazolides, giving similar yields (50%), but the benzotriazolides and benzimidazolides were not as effective. The o-nitrophenyl and p-chlorophenyl esters of propionic acid did not lead to any aromatic products.11185 Similar 5C + 1C condensation reactions are described in references [119] and [120],... 

G Kupryszewski, M Formela. Amino acid chlorophenyl esters. HI N-Protected amino acid pentachlorophenyl esters. Rocz Chem 35, 931, 1961. 

Halophenols are easier to dispose of by extraction. Chlorophenyl esters are resistant to hydrogenation and are hence compatible with benzyloxycarbonyl. Benzotriazolyl esters are unique in that they exist in two different forms (see Section 7.17). They are too reactive for routine use but are often employed without isolation after their preparation, using a carbodiimide or other (see Section 7.20). An exception to this are the benzotriazolyl adducts of. V-lrilylamino acids that are amide oxides (see Section 7.17), which are stable to aqueous sodium hydroxide but undergo aminolysis normally. 

The total cDNA construct of NPN43C9 was expressed efficiently in E. coli cells and protein purified, and its catalytic properties were assessed in both the monoclonal antibody and the single-chain antibody (scFv) 7A4-1/212 for the hydrolysis of p-nitroanilide [50] and the related p-chlorophenyl ester [51a] (Fig. 19). Virtually identical kca, and Km values were obtained for both 7A4-1/212 and NPN43C9. This activity was decreased in both cases by the addition of the inhibitor w-nitroanilide [52], which gave K = 800 p.M and 400 pM for the NPN43C9 and 7A4-1/212, respectively. 

CHLOROPHENYL ISOTHIOCYANATE (Isofhiocyanic acid, >-chlorophenyl ester)... 

Chlorophenyl trifluoromethanesulfonate Methanesulfonic acid, trifluoro-,j-chlorophenyl ester (8) Methanesulfonic acid, trifluoro-, 4-chlorophenyl ester (9) (29540-84-9) 4-Chlorophenol TOXIC Phenol, p-chloro- (8) Phenol, 4-chloro- (9) (106-48-9) Pyridine (8, 9) (110-86-1)... 

Fig. 8. pH measurement in cells. F NMR of difluoromethylalanine para-chlorophenyl ester (1 mM) added to suspension of RINmSF cells (4% cytocrit). Spectra were taken at... 

The rate of hydrolysis of a carboxylic ester in strong sulphuric acid generally shows one of the three types of dependence on acid concentration illustrated in Fig. 1. The simplest behaviour, a continuous increase in hydrolysis rate with increasing acid concentration, is shown by esters of tertiary alcohols, which are hydrolyzed very rapidly even in moderately concentrated acid, and by phenol esters, which are somewhat less reactive, but are hydrolyzed much faster than esters of simple primary and secondary alcohols with above about 60% H2S04. Substituted phenyl acetates behave very much like the parent compound, the p-chlorophenyl ester being hydrolyzed at almost the same rate as the unsubstituted compound, while p-nitrophenyl acetate is somewhat less reactive at low acid concentrations, but more reactive in above 70% sulphuric acid. 

SYNS m-CHLORFENYLISOKYANAT ISOCYANIC ACID-m-CHLOROPHENYL ESTER... 

SYNS p-CHLORFENYUSOKYANAT (CZECH) ISOCYANIC ACID-p-CHLOROPHENYL ESTER PCPI... 

S-(((p-CHLOROPHENYL)THIO)METHYL) 0,0-DI-METHYL PHOSPHORODITHIOATE S-(((4-CHLORO-PHENYL)THIO)METHYL) 0,0-DIMETHYLPH0SPH0R0-DITHIOATE DIMETHYL-p-CHLOROPHENYLTHIO-METHYL DITHIOPHOSPHATE 0,0-DIMETHYL-S-(p-CHLOROPHENTXTHIOMETHYL)PHOSPHORODITHIOA TE 0,0-DIMETHYLTHI0PH0SPH0RIC ACID, p-CHLOROPHENYL ESTER ENT 25,599 G-29288 GEIGY G-29288 METHYLCARBOPHENOTHION R-1492 STAUFFER R-1492 TRI-ME... 

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