摘要:
Phenolic compounds, notably admixtures of 2,4-dichlorophenol and 2,6-dichlorophenol, are selectively chlorinated at the ortho positions thereof, with gaseous chlorine and in a molten medium, in the presence of a selectivity-enhancing effective amount of an organic cation.
摘要:
Ortho-substituted phenolic compounds, e.g., 2,6-dichlorophenol, are selectively chlorinated, e.g., into 2,4,6-trichlorophenol, with gaseous chlorine in either the molten state or in a solvent medium, in the presence of a selectivity-enhancing effective amount of an organic cation.
摘要:
The chlorophenols, e.g., 2,4,6-trichlorophenol, are efficiently prepared by chlorinating an ortho-/para-substituted phenolic compound with gaseous chlorine, whether in molten state or in a solvent reaction medium, in the presence of a catalytically effective amount of a primary, secondary or tertiary amine.
摘要:
Process for preparing chloranil by the oxidative chlorination of a quinone or of a hydroquinone with a hydrochloric acid/hydrogen peroxide mixture, the introduction of hydrogen peroxide being carried out at a temperature above 60.degree. C.
摘要:
The chloronitrophenols, e.g., 2,6-dichloro-4-nitrophenol (a known agrochemical/pharmaceutical intermediate), are efficiently prepared by chlorinating ortho- or para-nitrophenol with gaseous chlorine, characteristically in the molten state, and in the presence of a catalytically effective amount of a primary, secondary or tertiary amine.
摘要:
The polychlorophenols, e.g., 2,6-dichlorophenol (a known agrochemical intermediate), are effectively prepared by chlorinating ortho-chlorophenol with gaseous chlorine, optionally in the presence of other chlorophenols, characteristically in the molten state, and in the presence of a catalytically effective amount of a primary, secondary or tertiary amine.
摘要:
The invention concerns quaternary ammonium compounds whereof the nitrogen bears a fluorine atom. Said ammonium compounds have an asymmetric carbon atom which is spaced from the ammonium function by not more than five members. The invention is useful for enantioselective electrophilic fluorination of various substrates.
摘要:
The invention concerns a halogenation in position meta of a phenol fuction. Said halogenation comprises a step which consists in halogenating an aromatic derivative of a medium or advantageously strong acid, the aromatic radical being a phenyl substituted in ortho and in para by functions attracting electrons by inductive effect. The invention is applicable to organic synthesis.
摘要:
A cosmetic or dermatological composition contains, in a physiologically acceptable medium, at least one compound from Formula (I). A method of using the composition, for reducing or preventing pigmenting, and/or whitening and/or lightening of the skin is described, as well as novel compounds from Formula (I′) that are included in Formula (I).
摘要:
The invention concerns a method for functionalizing a phenolic compound bearing an electron-donor group, in said group para position, inter alia a method for the amidoalkylation of a phenolic compound bearing an electron-donor group, and more particularly, a phenolic compound bearing an electron-donor group preferably, in the hydroxyl group ortho position. The method for functionalizing in para position with respect to an electron-donor group carried by a phenolic compound is characterised in that the phenolic compound bearing an electron-donor group is subjected to the following steps: a first step which consists of protecting the hydroxyl group in the form of a sulphonic ester function; a second step which consists in reacting the protected phenolic compound with an electrophilic reagent; optionally, a third step deprotecting the hydroxyl group.