Chloro phenols, functionalized

This group of pesticides comprises different families of chemicals with her-bicidal action including substituted phenols, chlorinated aliphatic acids, chloro-phenoxy alkanoic acids, and substituted benzoic acids, which possess carboxyl or phenolic functional groups capable of ionization in aqueous media to yield anionic species [47,151,168-170]. 

The naphthalene-catalyzed (3-12%) lithiation of deprotonated chloro phenols and anilides 236 performed with n-butylUthium in THF at 0 or —78 °C, respectively, gave the corresponding functionalized aryllithium intermediates 237 which, by reaction with electrophiles and final hydrolysis, yielded the corresponding polyfunctionalized molecules 238 (Scheme 79) . 

A separate experiment using 4-chlorocatechol as the starting compounc was performed to verify this reaction step. Figure 7 shows the oxidation of 4 chlorocatechol compared with that of 4-chlorophenol. The concentrations o hydroxyhydroquinone from the oxidation of 4-chlorocatechol and 4-chloro phenol as a function of time are also shown in Figure 7, which indicates tha the photocatalytic oxidation of 4-chlorocatechol yields hydroxyhydroquinom as the only significant intermediate. Step 5 of Scheme I shows that a contin... 

O-Protection of A-Boc-aspartic acid, serine, and threonine can be achieved by conversion into the 4-chloro-(or bromo-)benzyl derivatives, which are 5—7 times more stable than the corresponding simple benzyl derivatives in 5% TFA in methylene chloride, and are completely removed in liquid HF at 0°C in ten minutes. The usefulness of the o-nitrobenzyl (ONBzl) group for protection of the phenolic function in tyrosine has been discussed. Optimum conditions for its mild, photolytic cleavage have also been established. A xanthydryl group has been used to protect the amide function of asparagine during a decapeptide synthesis. ... 

A subsequent study, using clearly homogeneous conditions, of the dedeutera-tion of [2-2H]-4-nitro-, -chloro-, and -methyl-phenols by aqueous sulphuric acid showed that the rate coefficients clearly increased with increasing acidity (Table 120) and plots of log rate coefficient versus the acidity function — H0 were linear,... 

Figure 1 Degradation rate of phenol [36] and 3-chloro-4-hydroxybenzoic acid (CHBA) [35] as a function of its their concentration. (Adapted from Refs. 36 and 35, respectively see the references for experimental conditions.)...

Chloropyrimidines fused to benzoxazepines are versatile starting materials for development of inhibitors of specific kinases. Thus, the 1-chloro function of pyrimidooxazepine 102 could be substituted with heterocyclic amines <2005BML5474, 2005TL7523, 2006BML5102>, anilines, arylthiols, and phenols <2005JOC9629> to afford the substituted derivatives 103. In the same way, the 3-chloro function of pyrimidine 104 could be substituted (Scheme 12) <2005TL7523>. 

Therapeutic Function Antiseptic, Anthelmintic, Antifungal Chemical Name Phenol, 2,2 -methylenebis(4-chloro-Common Name Dichlorophen Structural Formula ... 

The synthetic potential of reductions by formate has been extended considerably by the use of ammonium formate with transition metal catalysts like palladium and rhodium. This forms a safe alternative to use of hydrogen. In this fashion it is possible to reduce hydrazones to hydrazines, azides and nitro groups to amines, to dehalogenate chloro-substituted aromatics, and to carry out various reductive removals of functional groups. For example, phenol triflates are selectively deoxygenated to the aromatic derivatives using triethylammonium formate as reductant and a palladium catalyst. - These recent af li-cations have been reviewed. 

Vanadium(IV) forms complexes with charged carboxylate, aryloxide and alkoxide functionalities as well as the neutral carbonyl group. The steric crowding of the /-butoxides allowed structural characterization of the tetraalkoxide (96) by gas-phase electron diffraction.475 Vw phenoxide complexes derived from ligands such as 2-(dimethylaminomethyl)phenol and 4-chloro-2-[(dimethylamino)methyl]phenol are active as ethylene and propylene copolymerization agents 476 Complexes with silanoxides have been prepared by the oxidation of Vnl complexes.477... 

The calculated local softnesses and Fukui functions of the fluoro- and chloro-substituted phenols (values of sf ) suggest the following protonation ordering (versus the real ordering found from calculated proton affinities). 

Cyclopropyl isocyanates react effectively with various nucleophilic reagents. Ammonia and amines yield urea derivatives, " alcohols and phenols afford carbama-tg5,i5 5,164,181,184,185 )V )y-dimethylhydrazine gives a semicarbazide derivative, whereas cyclo-propylammonium chlorides are obtained in refluxing hydrochloric acid. The yields are usually very good. When more highly functionalized nucleophiles are employed, such as the enolate from ethyl 4-chloro-3-oxobutanoate, more complex molecules can be obtained, e.g. the formation of furanone derivative 15. ... 

Side-chain halogen and 0-acylphenol functions interact under basic conditions to give a moderately good yield of benzofuran. An o-(2-chloroallyl)phenol is cyclized on wanning with mineral acid, but yields are only moderate for 6-chloro- and 6-methoxy-benzofuran. This type of cyclization may give higher yields in a strongly alkaline medium [3943]. This particular synthesis failed in cold sulphuric acid and in hot diethylaniline. 

For this functional group we will mention the non-volatile members, nevertheless excluding the chloro-genic acids (Section 2.1.4) and the phenolic compounds resulting from their degradation during roasting (Section 5.H). 

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