Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Substitution compounds

The white insoluble products are violently reactive, and slowly metalate even paraffin hydrocarbons. [Pg.52]

The new sodium t-butoxide method appears to be better, and works because LiOBu is soluble and RNa insoluble in paraffin solvents  [Pg.52]

The reaction between sodium and halides suffers from complications due to various exchange and coupling reactions, which can lead to a variety of products. One example, however has been developed into a satisfactory preparative method which may well find industrial application. This is the reaction between chlorobenzene and fine sodium dispersions (0-5-20 microns) in a hydrocarbon medium. [Pg.52]

Phenylsodium, which can be made continuously in one variation of this reaction has several attractions as a phenylating agent relative to phenyl-lithium or phenylmagnesium bromide, since both chlorobenzene and sodium are cheap (compared with bromobenzene and lithium) and Grignard reagents also need expensive solvents. [Pg.52]

Methyl-sodium (and -potassium) is more stable thermally than the higher alkyls, which decompose slowly at room temperature and rapidly at ca. 100° by loss of olefin, e.g.  [Pg.52]


The more extensive problem of correlating substituent effects in electrophilic substitution by a two-parameter equation has been examined by Brown and his co-workers. In order to define a new set of substituent constants. Brown chose as a model reaction the solvolysis of substituted dimethylphenylcarbinyl chlorides in 90% aq. acetone. In the case ofp-substituted compounds, the transition state, represented by the following resonance structures, is stabilized by direct resonance interaction between the substituent and the site of reaction. [Pg.138]

Here, and with the chlorotoluenes, the precise values for the calculated figures depend on the values adopted for the partial rate factors in the mono-substituted compounds. These and the relative rates do depend slightly on conditions. As has been pointed out several times previously, comparisons with benzene for nitration in sulphuric acid have to be made with care. [Pg.185]

A two-step synthesis of indoles from o-nitrobenzaldehydes proceeds by condensation with nitromcthanc followed by reductive cyclization. Like the Leim-gruber Batcho method, the principal application of the reaction is to indoles with only carbocyclic substituents. The forniation of the o,p-dinitrostyrenes is usually done under classical Henry condensation conditions but KF/18-crown-6 in propanol was found to be an advantageous reaction medium for acetoxy-substituted compounds[1]. The o,p-dinitrostyrenes can also be obtained by nitration of p-nitrostyrenes[2]. [Pg.11]

For this class of thiazoles most of the chemical and physicochemical studies are centered around the protomeric equilibrium and its consequences. The position of this equilibrium may be determined by spectroscopic and titrimetric methods, as seen in each section. A simple HMO (Hiickel Molecular Orbitals) treatment of 2-substituted compounds however, may, exemplify general trends. This treatment considers only protomeric forms 1 and 2 evidence for the presence of form 3 has never been found. The formation energy reported in Table 1 is the energy difference in f3 units. [Pg.2]

Aminoalkylation of N-[pyridyl-(2)]thiazolyl-(2)-amine yields the C-5-substituted compound (208) (Scheme 131) (132. 382. 383). [Pg.81]

Reaction takes place on nitrogen when the electrophilic center is an sp carbon, particularly if it is charged. Thus Mannich reaction yields the N-substituted compound (71 and 72) (Scheme 34) (54. 157-159). The same reaction is reported with piperidine, o-toluidine. and methylaniline (158). [Pg.394]

Thiazole sulfonic acid reacts with nucleophiles leading to the corresponding 2-substituted compounds (140. 141, and 142) (Scheme 73) (39, 334). [Pg.414]

Aminoselenazoles are crystalline compounds, and with the exception of the nonsubstituted derivative (1) they are stable and practically odorless. They are more basic than 2-aryl- or 2-alkylselenazoles. The hydrochlorides are not easily hydrolyzed in aqueous solution. Some of the K-substituted compounds are oily liquids. [Pg.230]

The peak near 3085 cm disappears only for 2.4-disubstituted derivatives. Its frequency is slightly higher for 2- than for 4-substituted compounds. The vC(2)H and vC(4,H vibrations seem to be nearly equivalent and usually give rise to an unique peak, except in the case of 5-bromo-and 5-isopropylthiazoles in CCI4 solution, where this peak is split into two bands. [Pg.64]

For the methyl-substituted compounds (322) the increase in AG and AHf values relative to the unsubstituted thiazole is interpreted as being mainly due to polar effects. Electron-donating methyl groups are expected to stabilize the thiazolium ion, that is to decrease its acid strength. From Table 1-51 it may be seen that there is an increase in AG and AH by about 1 kcal mole for each methyl group. Similar effects have been observed for picolines and lutidines (325). [Pg.93]

An old name for benzene was phene and its hydroxyl derivative came to be called phe nol This like many other entrenched common names is an acceptable lUPAC name Likewise o m and p cresol are acceptable names for the various ring substituted hydroxyl derivatives of toluene More highly substituted compounds are named as deriv atives of phenol Numbering of the ring begins at the hydroxyl substituted carbon and proceeds m the direction that gives the lower number to the next substituted carbon Sub stituents are cited m alphabetical order... [Pg.993]

Two classes of fat replacers exist mimetics, which are compounds that help replace the mouthfeel of fats but caimot substitute for fat on a weight for weight basis and substitutes, compounds having physical and thermal properties similar to those of fat, that can theoretically replace fat in all appHcations (46). Because fats play a complex role in so many food appHcations, one fat replacer is often not a satisfactory substitute. Thus a systems approach to fat replacement, which reHes on a combination of emulsifiers, gums, and thickeners, is often used. [Pg.439]

A number of organic derivatives of gallane, both addition and substitution compounds, ate known. Some ate much mote stable than gallane, eg,... [Pg.162]

Carbon—nitrogen double bonds in imines, hydrazones, oximes, nitrones, azines, and substituted diazomethanes can be cleaved, yielding mainly ketones, aldehydes and/or carboxyHc acids. Ozonation of acetylene gives primarily glyoxal. With substituted compounds, carboxyHc acids and dicarbonyl compounds are obtained for instance, stearoHc acid yields mainly azelaic acid, and a smaH amount of 9,10-diketostearic acid. [Pg.493]

The dye can be formulated by means of a phosgene (qv) (67,68). Chloromethylation leads to the alkylated polymethines nitration of cyanines results ia mononitro-substituted compounds (66). [Pg.495]

Hypochlorite readily chlorinates phenols to mono-, di-, and tri-substituted compounds (163). In wastewater treatment chlotophenols ate degraded by excess hypochlorite to eliminate off-flavor (164). Hypochlorite converts btomoben2ene to cb1oroben2ene in a biphasic system at pH 7.5—9 using phase-transfer catalysts (165). [Pg.469]

The photochemical ring closure of certain stilbenes, eg, the highly methyl substituted compound (2) [108028-39-3], C22H2g, and their heterocycHc analogues is the basis for another class of photochromic compounds (31—33). [Pg.164]

Cinnolin-3(2//)-one (7) is methylated with diazomethane or methyl sulfate to give 2-methylcinnolin-3(2H)-one. In a similar manner, benzylation with benzyl chloride, cyanoethylation with acrylonitrile in the presence of benzyltrimethylammonium hydroxide and glucosidation with tetra-O-acetyl-a-o-glucopyranosyl bromide in the presence of a base affords the corresponding 2-substituted cinnolin-3(2//)-ones. However, glucosidation of the silver salt of cinnolin-3(2//)-one produces the corresponding O-substituted compound. [Pg.16]

The y-CH modes arising from out-of-plane C H deformations should be characteristic of the substitution pattern and the observed frequencies are summarized in Table 23. For 2-substituted compounds these may be assigned as (31), (32) and (33). Additional characteristic bands for 2-substituted thiophenes are observed at 870-840m and 740-690s cm (67RTC37). ... [Pg.19]

Isothiazole has an absorption maximum in ethanol solution at 244 nm, with a molar absorptivity of 5200. This absorption occurs at a longer wavelength than with pyrazole or isoxazole, the displacement being due to the presence of the sulfur atom. A series of approximate additive wavelength shifts has been drawn up in Table 11 and this should enable prediction of UV maxima of isothiazoles with reasonable accuracy, even for multiply substituted compounds. The longest wavelength band results from a electronic... [Pg.140]

The isothiazole ring is very stable to moderate heating, but quaternized compounds are dequaternized by this means (see Section 4.02.3.12). Photolysis of isothiazole itself causes loss of hydrogen cyanide, forming thiirene, but substituted compounds are converted into mixtures of thiazoles and isothiazoles isomeric with the starting compound (Section 4.1.1.2). [Pg.146]

Diaziridines also show slow nitrogen inversion, and carbon-substituted compounds can be resolved into enantiomers, which typically racemize slowly at room temperature (when Af-substituted with alkyl and/or hydrogen). For example, l-methyl-3-benzyl-3-methyl-diaziridine in tetrachloroethylene showed a half-life at 70 °C of 431 min (69AG(E)212). Preparative resolution has been done both by classical methods, using chiral partners in salts (77DOK(232)108l), and by chromatography on triacetyl cellulose (Section 5.08.2.3.1). [Pg.7]

The stereochemistry of addition is usually anti for alkyl-substituted alkynes, whereas die addition to aryl-substituted compounds is not stereospecific. This suggests a termo-iecular mechanism in the alkyl case, as opposed to an aryl-stabilized vinyl cation mtermediate in the aryl case. Aryl-substituted alkynes can be shifted toward anti addition by including bromide salts in the reaction medium. Under these conditions, a species preceding the vinyl cation must be intercepted by bromide ion. This species can be presented as a complex of molecular bromine with the alkyne. An overall mechanistic summary is shown in the following scheme. [Pg.375]

In the previous sections the various possibilities for the production of 19-norsteroids from 19-substituted compounds have been reviewed. It is virtually impossible to compare the efficiency of the various procedures since optimal conditions are usually not described. [Pg.278]


See other pages where Substitution compounds is mentioned: [Pg.447]    [Pg.1076]    [Pg.712]    [Pg.509]    [Pg.542]    [Pg.929]    [Pg.1059]    [Pg.184]    [Pg.32]    [Pg.217]    [Pg.116]    [Pg.273]    [Pg.273]    [Pg.252]    [Pg.456]    [Pg.204]    [Pg.11]    [Pg.21]    [Pg.109]    [Pg.35]    [Pg.192]    [Pg.146]    [Pg.168]    [Pg.254]    [Pg.694]    [Pg.1061]   
See also in sourсe #XX -- [ Pg.552 , Pg.1011 ]




SEARCH



4"-amino-substituted second-generation compounds

7-Substituted fused ring tetracycline compounds

A-hetero-substituted organic electrophiles mercury compounds

A-hetero-substituted organic electrophiles tin compounds

A-hetero-substituted organic electrophiles zinc compounds

Acetylene-substituted Si-N-P compounds

Active hydrogen compounds aromatic nucleophilic substitution

Addition, Condensation and Substitution Reactions of Carbonyl Compounds

Advances in homolytic substitution of heteroaromatic compounds

Aliphatic halogen compounds nucleophilic substitution

Allyl compounds, nucleophilic substitution

Allylic derivatives 3-hetero-substituted compounds

Allylic substitutions propargyl compounds

Allyltin compounds substitution reactions

Alpha Substitutions of Carbonyl Compounds

Aluminum compounds conjugate substitution

Amine-substituted diboron compounds

Ammonium compounds, substituted

Ammonium compounds, substituted salts

Ammonium compounds, substituted tetramethyl— dichloroiodate

Aromatic Compounds Through Intramolecular Electrophilic Substitution

Aromatic Compounds—Substituted Benzene Rings

Aromatic Halogen Compounds Substituted in the Side hain

Aromatic compounds alkyl-substituted

Aromatic compounds electrophilic substitution

Aromatic compounds electrophilic substitution reactions

Aromatic compounds substituted aromatics

Aromatic compounds substitutents

Aromatic compounds substitution

Aromatic compounds substitution reactions

Aromatic compounds, addition substitution reactions

Aromatic compounds, nucleophilic substitution

Aromatic compounds, polycyclic, electrophilic substitution

Aromatic compounds, substituted

Aromatic compounds, substituted metabolites

Aromatic compounds, substituted nucleophilic reactions

Azinium compounds, N-alkyl-, substituent displacement kinetics of substitution

Boron-substituted heteroaromatic compounds

Bridged compounds 2], axial substitution

Carbon-substituted compounds - carbamoyl phosphate

Carbonyl compounds a-heteroatom-substituted

Carbonyl compounds a-substituted

Carbonyl compounds nucleophilic substitution

Carbonyl compounds substituted acetic acids, synthesis

Carbonyl compounds substitution reactions

Carbonyl compounds substitutions

Carbonyl compounds substitutive

Carbonyl compounds, addition reactions substituted imine formation

Compound libraries substitutional diversity

Compounds Derived from S-Substituted Mercaptoacetic Acids

Compounds Derived from Substituted Aminoacetic Acids

Compounds Derived from Substituted Phenoxyacetic Acids

Compounds Derived from Substituted Phenylacetic Acids

Condensations and Alpha Substitutions of Carbonyl Compounds

Coordination compounds ligand substitution

Coordination compounds substituted hydrazines

Coordination compounds substitution reactions

Copper compounds Cu in aromatic nucleophilic substitution

Dideaza compounds with N substitution

Disilyl-substituted compounds

Dissociative substitution reactions octahedral compounds

Ei-ichi Negishi 2 Palladium-Catalyzed Cross-Coupling nvolving 3-Hetero-Substituted Compounds Other than Enolates

Electrophilic Substitution Reactions on Metalated Aromatic Compounds

Electrophilic Substitution of Compounds Containing Several Thiophene Rings

Electrophilic and Nucleophilic Substitution at the C(a)-Atom of Diazo Compounds

Electrophilic aromatic substitution of heteroaromatic compounds

Electrophilic substitution aryl Grignard compounds

Electrophilic substitution aryllithium compounds

Electrophilic substitution compounds

Electrophilic substitution is the usual route to substituted aromatic compounds

Electrophilic substitution of aromatic compounds

Electrophilic substitutions of allyl-metal compounds

Enolate compounds nucleophilic substitution

Fen-Tair Luo 14 Palladium-Catalyzed Cross-Coupling Involving 3-Hetero-Substituted Compounds

Fluoro-substituted compounds

Free radical substitutions of heteroaromatic compounds

Functional compounds substitutive nomenclature

Functionally Substituted Bistetraorganotin Compounds

Functionally Substituted Compounds

Functionally Substituted Cyclic Tetraorganotin Compounds

Functionally Substituted Tetraorganolead Compounds

Fused-ring compounds aromatic substitution

GeR4 Compounds with R Substituted Alkyl

Germanium compounds ligand substitution

Gold compounds ligand substitution

Halogen-substituted compounds

Halogenation substituted aromatic compounds

Heteroaromatic compounds electrophilic aromatic substitution

Heteroaromatic compounds homolytic substitution

Heteroaromatic compounds, free-radical substitutions

Heteroaromatics 3-hetero-substituted compounds

Heteroaryl-substituted compounds

Heteroatom-substituted aromatic compounds

Heterocyclic Substituted Tetraorganolead Compounds

Heterocyclic Substituted Tetraorganotin Compounds

Heterocyclic compounds electrophilic aromatic substitution

Heterocyclic compounds electrophilic substitution

Heterocyclic compounds formation from saturated substituted

Heterocyclic compounds halogen-substituted, reduction

Heterocyclic compounds nucleophilic aromatic substitution

Heterocyclic compounds substituted thiazoles

Heterocyclic compounds substitution

Heterocyclic compounds substitution reactions

Heterocyclic compounds vinyl substitutions

Highly substituted aromatic compounds

Homocoupling and Oxidative Substitution Reactions of Aromatic Compounds

Homolytic substitution of heteroaromatic compounds

Hydride compounds nucleophilic substitution

In homolytic substitution of heteroaromatic compounds

Iron compounds ligand substitution

Isotopes substituted compounds

Isotopically substituted compounds

Isotopically substituted compounds formulae

Ligand substitution reactions compounds

Long chain laterally substituted compounds

Long-chain alkyl-substituted heterocyclic compounds

Malonate compounds nucleophilic substitution

Meta substitution, definition compounds

Meta-substituted compounds, spectra

Metal groups 3-hetero-substituted compounds

Methylene substituted cyclic compounds

Nitro compounds aromatic, nucleophilic substitution

Nitro compounds halogen-substituted aromatic, reduction

Nitro compounds substitution

Nitrogen Substituted Organogermyl Tin Compounds

Nitrogen-substituted compounds

Nitroso compounds substitution

Norbomyl compounds nucleophilic substitution

Nucleophilic acyl substitution carbonyl compound

Nucleophilic substitution allylic compounds

Nucleophilic substitution five-membered ring compounds

Nucleophilic substitution miscellaneous compounds

Nucleophilic substitution process nitrogen compounds

Nucleophilic substitution propargylic compounds

Nucleophilic substitution reaction aromatic compounds

Nucleophilic substitution reactions compounds

Nucleophilic substitution sulphur compounds

Nucleophilic substitution three-member ring compounds

Nucleophilic substitution, hypervalent silicon compounds

Nucleophilic substitution—continued mechanisms for aromatic compounds

Organic Halogen Compounds Substitution and Elimination Reactions

Organic compounds substitution reactions

Organic compounds substitutive-type nomenclature

Organocopper compounds substitution

Organolithium compounds aromatic nucleophilic substitution

Organolithium compounds substitution

Organomercury compounds vinyl substitutions

Organometallic Compounds Substitution

Organometallic Compounds Substitution 1 Exchange Reactions

Organometallic compounds aromatic nucleophilic substitution

Organometallic compounds electrophilic substitution

Organometallic compounds substitution polymerization

Organometallic compounds substitution reactions

Organopalladium compounds vinyl substitutions

Organosilicon compounds nucleophilic substitution reactions

Organosilicon compounds silicate substitution

Ortho substitution, definition compounds

Oxidative substitution, aromatic compounds

Oxo and Hydroxy Side-chain Substituted Compounds

Oxygen compounds acetal substitution

Oxygen-substituted compounds - peroxomonophosphate

P-Substituted carbonyl compound

P-substituted aromatic compounds

Para-substituted compounds, spectra

Partial rate factors for hydrogen exchange in some substituted aromatic compounds

Pentacoordinate silicon compounds nucleophilic substitution

Pentafluorophenyl-substituted compounds

Propargyl compounds substitutions with

Pyridinium compounds substitution

REACTIONS BETWEEN ELEMENTS AND COMPOUNDS SUBSTITUTION BY NEGATIVE IONS

REACTIONS BETWEEN ELEMENTS AND COMPOUNDS SUBSTITUTION BY POSITIVE IONS

Radical Reactions of Aromatic Compounds with Captodative Substitution

Reactions of Aromatic Compounds Electrophilic Substitution

Recent Michael-Type Reactions Using Chirally Modified ,-Substituted Carbonyl Compounds

Reduction a-substituted carbonyl compounds

Ring compounds bridged substitution

Ring compounds fused substitution

Ring compounds spiro substitution

SUBSTITUTIONS IN ORGANOMERCURY COMPOUNDS

SYNTHESIS OF SUBSTITUTED AROMATIC COMPOUNDS

Silicon compounds silane electrophilic substitution

Silver-substituted diazomethyl compounds

Simple Substituted Compounds

Substituted Alkyl Compounds

Substituted Compounds

Substituted Compounds

Substituted Monocyclic Compounds

Substituted benzenes aromatic compounds

Substituted imidazole compounds

Substituted systems compound

Substitution Reactions of Carbonyl Compounds at the a Carbon

Substitution Reactions on Aromatic Compounds

Substitution at carbon by organomagnesium compounds

Substitution in Coordination Compounds

Substitution in Heterocyclic Aromatic Compounds

Substitution in aromatic compounds

Substitution of Monocarbonyl Compounds

Substitution reactions asymmetric, with zinc compounds

Substitution reactions nitro compounds as reactants

Substitution reactions of aromatic compounds

Substitution reactions organolithium compounds with

Substitution reactions with zinc compounds

Substitutive Alkylation of a-Halocarbonyl Compounds

Sulfur compounds substitution

Summary of Data for Methyl-substituted Compounds

Synthesis of Biologically Active Compounds via Allylic Substitution

Synthesis of substituted quinones via organotellurium compounds

Thio-substituted compound reductions

Thiocarbonyl-substituted compound

Thioether-substituted compounds

Trimethylsilyl-substituted compounds

Unsymmetric Tetraorganotin Compounds Containing Functionally Substituted Acetylenes

Unsymmetric Tetraorganotin Compounds Containing Functionally Substituted Olefins

Unsymmetric Tetraorganotin Compounds Containing Halogen Substituted Acetylenes

Unsymmetric Tetraorganotin Compounds Containing Halogen Substituted Olefins

Uranocene substituted compounds

Vinyl compounds alkyl substituted

Vinyl compounds aryl substituted

Vinyl compounds, nucleophilic substitution

Vinyl substituted cyclic compounds

Vinyltin compounds substitution reactions

© 2024 chempedia.info