Abstract:
Selective bromination of alkylarenes to the alpha dibrominated derivative is desirable as a precursor for the selective production of, for example, the corresponding aromatic aldehyde.Improvements in the extent of selectivity of the product and/or its rate of production can be obtained by employing a photolytic reaction between the substrate, hydrogen peroxide and hydrogen bromide using mole ratios of H.sub.2 O.sub.2 : substrate of about 2.8:1 or higher, preferably 3,2: to 3.5:1 and of bromide:substrate of over 2.5:1, preferably about 2.8:1 to 3.2:1 and progressive controlled introduction of the H.sub.2 O.sub.2, the reaction being carried out in the presence of a substantial amount of an organic solvent, and preferably more than 5.5 volumes per volume of substrate, whilst irradiating with light preferably having principal emissions in the range of 250 to 600 nm. The reaction mixture is preferably maintained at 50.degree. to 60.degree. C. The reaction often takes from 5 to 12 hours, of which period hydrogen peroxide is introduced progressively into the reaction mixture during preferably the first 3 to 5 hours. The process is especially suitable for deactivated alkylarenes, such as o-nitrotoluene.
Abstract:
Alkylidene compounds and arylidene compounds are prepared by reacting the corresponding CH-acidic compounds with carbonyl compounds in the presence of a catalyst comprising a metal compound of a metal of Groups IIA, IIIA, IVA, IB, IIB, VIB, VIIB, or VIIIB of the periodic table of elements. The rate of reaction is increased by adding 1 to 40% water referred to the weight of catalyst used.
Abstract:
A process for selectively forming nitrohydrocarbon compounds by contacting, at elevated temperature and pressure and in a homogeneous gas phase, an olefinic unsaturated compound having at least three carbon atoms with NO.sub.2 alone or in the presence of oxygen and/or water.
Abstract:
A process for selectively forming nitroalkanes and nitroaromatics by contacting, at elevated temperature and pressure and in a homogeneous gas phase, an organic carboxylic acid having from two to ten carbon atoms with NO.sub.2 alone or in the presence of oxygen and/or water.
Abstract:
An improved process for forming nitroparaffins by gaseous phase nitration of hydrocarbons higher than methane. The improvement comprises carrying out the nitration in the presence of a small amount of at least one carboxylic acid, preferably acetic acid.
Abstract:
THE INVENTION RELATES TO A PROCESS FOR THE PRODUCTION OF NITROPARAFFINS FROM HYDROCARBONS HIGHER THAN METHANE, BY NITRATION WITH NITROGEN PEROXIDE IN THE PRESENCE OF OXYGEN, INTRODUCED IN THE FORM OF AIR, WHEREIN THE NITRATION IS CARRIED OUT AT A PRESSURE WHICH IS BETWEEN 8 AND APPROXIMATELY 14 BARS, THE REACTANT GASES BEING PREHEATED UNDER THE REACTION PRESSURE AND INTRODUCED INTO THE REACTION ZONE BETWEEN 150 AND 330*C., THE GASEOUS EFFLUENTS ORIGINATING FROM THE NITRATION ZONE BEING SUBJECTED TO A RAPID COOLING OR QUENCHING.
Abstract:
The present disclosure relates to compounds of Formula (I): and to their pharmaceutically acceptable salts, pharmaceutical compositions, methods of use, and methods for their preparation. The compounds disclosed herein are useful for inhibiting the maturation of cytokines of the IL-1 family by inhibiting inflammasomes and may be used in the treatment of disorders in which inflammasome activity is implicated, such as autoinflammatory and autoimmune diseases and cancers.
Abstract:
Disclosed herein is a simple process for functionalization/grafting of carbon microspheres obtained from bagasse with various active functional groups onto it and use of the same as catalyst for various organic reactions, having very high selectivity and conversion rate.
Abstract:
The present invention provides desosamine and mycaminose analogs and nitro sugars and methods for their preparation. The invention also provides methods of cyclizing a compound of Formula (A′) with glyoxal to give a nitro sugar of Formula (B). Methods for the preparation of compound of Formula (D′) are provided comprising cyclization of a nitro alcohol to give a nitro sugar and reduction and alkylation of the nitro sugar to give a desosamine, mycaminose, or an analog thereof.