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Phenyl-substituted

Due to the structure of the symmetrical anhydrobase. every time a 2-methylthiazolium undergoes the attack of a base, theoretically it can result in two trimethine thiazolocyanines the mesomethylsubstituted one and the unsubstituted one. For an unexplained reason, it seems that when position 5 of the starting molecule is substituted, only the mesomethyl dye is produced according to the absorption spectrum, 530 nm for the methylmeso and 569 nm for the 4-phenyl substituted derivative (Scheme 29). ... [Pg.47]

The basicity of a 4-phenyl-substituted thiazole is less than the corresponding methyl-substituted thiazole (16) and the pKa values of quaiemarv salts are in the same order (25). [Pg.75]

The salts of derivatives possessing phenyl substitutents on the selenazole ring are easily hydrolyzed in aqueous solution. [Pg.234]

The free-radical reactivity of thiazoles has been well studied with various radicals such as methyl, phenyl, substituted phenyl, cyclohexyl, and aromatic-heterocyclic, in nonpolar solvent or strong acids (180-182). [Pg.364]

The results of phenyl substitution of difierent alkyl and arylthiazoles are given in Tables III-26 and III-27. [Pg.366]

The birefringence for phenyl-substituted PC (4) (T = 176 C) is reduced to about 50%, for benzyl substituted PC (5) (T = 138 C) to about 25%, and for four-ring bisphenol PC (6) to 8% of the value for BPA-PC (183,190,195,197,198) on condition of an optimum conformation of the phenyls in the side groups perpendicular to the aromatic rings in the backbone. In reaUty, however, these low birefringence values are not achieved, because the optimum conformation of the phenyl rings cannot be achieved in injection-stamped disks. [Pg.158]

More recently, test products were created of a blend of PMMA with a phenyl-substituted methacrylate these products have a glass-transition temperature of around 125°C, a significantly reduced water absorption compared to pure PMMA of about 0.32%, but also a higher birefringence (a stress-optic coefficient of 5.2 X 10 , compared with 0.3 X 10 for PMMA and 6.8 x 10 for BPA-PC). [Pg.161]

Phenyllithium can be used in Grignard-type reactions involving attachment of phenyl group, eg, in the preparation of analgesics and other chemotherapeutic agents (qv). It also may be used in metal—metal interconversion reactions leading, eg, to phenyl-substituted siUcon and tin organics. [Pg.229]

Many of the unique properties of siUcone oils are associated with the surface effects of dimethylsiloxanes, eg, imparting water repeUency to fabrics, antifoaming agents, release liners for adhesive labels, and a variety of poHshes and waxes (343). Dimethylsilicone oils can spread onto many soHd and Hquid surfaces to form films of molecular dimensions (344,345). This phenomenon is greatly affected by even small changes in the chemical stmcture of siloxane in the siloxane polymer. Increasing the size of the alkyl substituent from methyl to ethyl dramatically reduces the film-forming abiUty of the polymer (346). The phenyl-substituted siUcones are spread onto water or soHd surfaces more slowly than PDMS (347). [Pg.52]

Various racemic secondary alcohols with different substituents, eg, a-hydroxyester (60), are resolved by PFL neatly quantitatively (75). The effect of adjacent unsatuiation on enzyme-catalyzed kinetic resolutions was thoroughly studied for a series of aHyUc (61), propargyUc (62), and phenyl-substituted 2-aIkanols (76,77). Excellent selectivity was observed for (E)-aHyhc alcohols whereas (Z)-isomers showed poor selectivity (76). [Pg.340]

Pyridazines form complexes with iodine, iodine monochloride, bromine, nickel(II) ethyl xanthate, iron carbonyls, iron carbonyl and triphenylphosphine, boron trihalides, silver salts, mercury(I) salts, iridium and ruthenium salts, chromium carbonyl and transition metals, and pentammine complexes of osmium(II) and osmium(III) (79ACS(A)125). Pyridazine N- oxide and its methyl and phenyl substituted derivatives form copper complexes (78TL1979). [Pg.37]

Another approach uses the reaction of 6-chloro-5-nitropyrimidines with a-phenyl-substituted amidines followed by base-catalyzed cyclization to pteridine 5-oxides, which can be reduced further by sodium dithionite to the heteroaromatic analogues (equation 97) (79JOC1700). Acylation of 6-amino-5-nitropyrimidines with cyanoacetyl chloride yields 6-(2-cyanoacetamino)-5-nitropyrimidines (276), which can be cyclized by base to 5-hydroxypteridine-6,7-diones (27S) or 6-cyano-7-oxo-7,8-dihydropteridine 5-oxides (277), precursors of pteridine-6,7-diones (278 equation 98) (75CC819). [Pg.316]

Irradiation of isothiazole gives thiazole in low yield. In phenyl-substituted derivatives an equilibrium is set up between the isothiazole (59) and the thiazole (61) via intermediate (60) (72AHC(14)l). [Pg.47]

Diaziridinimines were made analogously. Tri-t-butylguanidine (281) with r-butyl hypochlorite gave (176) in 80% yield. (281) itself is a sufficiently strong base to deprotonate its Af-chloro derivative (69AG(E)448). This procedure also works with methyl- or phenyl-substituted guanidines. [Pg.232]

These groups, along with a number of other trialkylsilylethyl derivatives, were examined for protection of phosphorothioates. Only the phenyl-substituted silyl derivative was useful, because simple trialkylsilyl derivatives were prone to acid-catalyzed thiono-thiolo rearrangement. Other trialkylsilylethyl derivatives also suffer from inherent instability upon storage,but the trimethylsilylethyl group has been used successfully in the synthesis of the very sensitive agrocin 84 and for intemucleotide phosphate protection with the phosphoramidite approach. [Pg.676]

Two independent molecular orbital calculations (HMO method) of delocalization energies for isoindole and isoindolenine tautomers agree that the isoindole form should possess the more resonance stabilization. The actual difference calculated for isoindole-isoindolenine is about 8 kcal/mole, but increases in favor of the isoindole with phenyl substitution at position 1 (Table VI).Since isoindole and isoindolenine tautomers have roughly comparable thermodynamic stabilities, the tautomeric proce.ss is readily obser-... [Pg.132]

Less reactive electrophilic reagents like those involved in acylation or alkylation apparently do not react with phenyl-substituted pyrylium salts the p-acylation of a phenyl group in position 3 of the pyrylium salt obtained on diacylation of allylbenzene (Section II, I), 3, a), and the p-l-butylation of phenyl groups in y-positions of pyrylium salts prepared by dehydrogenation of 1,5-diones by means of butyl cations (Section II, B, 2, f) probably occur in stages preceding the pyrylium ring closure. [Pg.252]

The cyclization of ynaminoketones with hydrazine and its alkyl- and phenyl-substituted derivatives has been covered in a number of publications (69HCA2641 76H1921 87ZOR1635). [Pg.243]

The mass spectral fragmentations of 9,10-dimethoxy-2,3,4,6,7,ll/)-hexa-hydro-l//-pyrimido[6,l-n]isoquinolin-2-ones 140 and -2,4-diones 141, under electron ionization (at 70 eV) were examined by metastable ion analysis, a collosion-induced dissociation technique and exact mass measurement (97RCM1879). Methyl substituent on N(3) in 140 (R = Me) had a larger effect on both the fragmentation and on the peak intensities, than a methyl substituent on C(6) (R = Me). The ionized molecules of 140 (R = H) were rather stable, whereas 4-phenyl substitution on C(4) of 140 (R = Ph) promoted the fragmentations of the molecular ions. The hexahydro-1//-pyrimido[6,l-n]isoquinoline-2,4-diones 141 were more stable, than the hexahydro-l//-pyrimido[6,l-n]isoquinolin-2-ones 140, and the molecular ions formed base peaks. [Pg.248]

The parent TMM precursor (1) reacts with tropones (117) to give reasonable yields of the bridged [4.3.1]decanones (118) [43]. Various substituted TMMs also cycloadd to tropone with regioselectivity similar to that of the corresponding [3+2] cases [20, 43]. Addition of MesSnOAc as a co-catalyst also leads to yield improvement [16]. In the case of a phenyl-substituted tropone and a methyl-TMM, performing the reaction under high pressure favors the formation of kinetic products (119) and (120) over the thermodynamic product (121) [11]. [Pg.81]

With comprehensive GC, we can now choose a rational set of columns that should be able to tune the separation. If we accept that each column has an approximate isovolatility property at the time when solutes are transferred from one column to the other, then separation on the second column will largely arise due to the selective phase interactions. We need only then select a second column that is able to resolve the compound classes of interest, such as a phase that separates aromatic from aliphatic compounds. If it can also separate normal and isoalkanes from cyclic alkanes, then we should be able to achieve second-dimension resolution of all major classes of compounds in petroleum samples. A useful column set is a low polarity 5 % phenyl polysiloxane first column, coupled to a higher phenyl-substituted polysiloxane, such as a 50 % phenyl-type phase. The latter column has the ability to selectively retain aromatic components. [Pg.96]


See other pages where Phenyl-substituted is mentioned: [Pg.279]    [Pg.539]    [Pg.531]    [Pg.20]    [Pg.76]    [Pg.210]    [Pg.83]    [Pg.273]    [Pg.514]    [Pg.539]    [Pg.310]    [Pg.63]    [Pg.697]    [Pg.244]    [Pg.365]    [Pg.398]    [Pg.110]    [Pg.175]    [Pg.234]    [Pg.110]    [Pg.76]    [Pg.163]    [Pg.518]    [Pg.340]   


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2- Phenyl-5-substituted pyrazol-3-ones

2- Phenyl-5-substituted pyrazol-3-ones preparation

2- Substituted-5-phenyl-6//-1,3,4-thiadiazine

2- phenyl-4-substituted- 1-pyrroline

2-Ethoxycarbonyl-4-phenyl-6-substituted

2-phenyl substituted oxazolines

2-phenyl-4-substituted derivatives, ring

2-phenyl-4-substituted derivatives, ring opening

2-phenyl-4-substituted-5 -oxazolones

3- Phenyl-2-butanones, substituted

3- Phenyl-5-substituted isoxazoles

4- phenyl-, radical substitution

4-substituted phenyl isocyanates

5- Phenyl disulfides, substituted, to protect thiols

A-Phenyl substitution

Adenylate cyclase substituted-phenyl

Alcohols, phenyl-substituted

Alkanethiols phenyl-substituted

Alkenes phenyl-substituted bicyclic

Amides phenyl-substituted, formation

Aromatic substituted phenyl

Aromatic substituted phenyl epoxides

Cyclopropanes Substituted with Phenyl(Aryl) Groups

Effects 1-phenyl group substitution

Epoxidation, phenyl-substituted

Ethyl phenyl ether, substituted

Fatty acid phenyl-substituted

Heck coupling phenyl-substituted

Heterocycles, phenyl-substituted, nitration

Hydrogenation, phenyl-substituted

Ketones 2-phenyl-4-substituted oxazoles

Light emitting polymers phenyl substituted PPVs

Methyl phenyl ketone, substituted

Monocarboxylic acids phenyl-substituted

Nitration of phenyl-substituted heterocycles

Nomenclature phenyl substituted

Oxazoles, 2-phenyl-4-substituted

Phenyl -amine, substituted

Phenyl Substituted Silicon Hydrides

Phenyl azide substituted

Phenyl bromide substituted

Phenyl fluoro-substituted

Phenyl group, substitution

Phenyl groups, substituted

Phenyl groups, substituted, electronic effects

Phenyl hydroperoxide, substituted

Phenyl radicals aromatic substitution

Phenyl radicals, reactions rates with substituted

Phenyl ring substituted aniline

Phenyl substituted 2-butyl-2-cyanO

Phenyl substituted cyclohexanones

Phenyl substituted mesogens

Phenyl substituted p-hydroxybenzoates

Phenyl substituted poly

Phenyl substituted poly acetylene

Phenyl substituted polyphenylene

Phenyl substituted polythiophenes

Phenyl various substituted

Phenyl-Substituted Alkenes

Phenyl-azolones, electrophilic substitution often occurs in the benzene

Phenyl-substituted PPV

Phenyl-substituted Phosphonitrile Fluoride Trimers

Phenyl-substituted acetylenic

Phenyl-substituted cyclic enaminones

Phenyl-substituted epoxides

Phenyl-substituted ladder-type

Phenyl-substituted ladder-type poly

Phenyl-substituted phenols

Phenyl-substituted phosphite

Phenyl/methyl-substituted alkenes

Polyamides Phenyl-substituted

Polyimide phenyl-substituted

Polymer structure, phenyl-substituted

Regioselectivity phenyl substituted alkenes

Silyl-substituted phenyl cation

Site selectivity phenyl substituted alkenes

Substituted dialkyl-phenyl phosphates and phosphorothioates

Substituted methyl phenyl sulfoxides

Substituted phenyl benzoates

Substituted phenyl benzoates hydrolysis

Substituted-Phenyl Glycosides

Substitution in the phenyl ring

Vanadyl Porphine Phenyl Substituted

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