نتایج جستجو برای: good yields
تعداد نتایج: 506625 فیلتر نتایج به سال:
Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 by reaction with aromatic amines at room temperature in good to excellent yields. Imidate was prepared by treatment of equimolar quantities of triethyl orthoformate and diaminomaleonitrile in refluxing dioxane. All the compounds were characterized fully by ...
The cyclization of b-anilino propionic acids in the presence of polyphosphoric acid (PPA) afforded the 2,3-Dihydroquinoline-4-(1H)-ones in good yields. N,N'-bis(2-carboxyethyl)-4-methyl-1,2-diaminobenzene (7) is cyclized under this condition to produce the 1,5-diaza-2,3,6,7-tetrahydro-4-methyl-pheranthrene-4,8-dione(bis-quinolone) (8).
Nano silica-H2SO4 is an efficient and mild catalysis system for the regeneration of aldehyde from aldoximes. Ketoximes are converted to amides by Beckmann rearrangement in the presence of nano silica-H2SO4. The reactions are carried out in solvent-free conditions under microwave irradiation (600 W) within 50-120 sec in good yields.
A convenient synthesis of different types of polyfunctional dihydropyrrol-2-ones via one-pot four component reactions of formaldehyde, dialkyl acetylenedicarboxylates and amines, catalyzed by trichloroacetic acid (Cl3CCO2H) at room temperature has been investigated. The significant advantages of this synthetic method are mild reaction conditions, available and inexpensive material, short reacti...
1,4-bis(triphenyl phosphonium)butane peroxodisulfate(BTPPBPDS) were synthesized by treating 1,4-bis(triphenyl phosphonium)butane dibromide and potassium peroxydisulfate in aqueous solution.This was used mild and efficient reagent for oxidation of alkyl benzenes to their corresponding carbonyl compounds in very good to high yields.
An efficient and expeditious catalyst-free procedure was developed for the one- pot synthesis of 1, 4-dihydropyridine derivatives via the three-component reaction of various aldehydes, ethyl acetoacetate, and ammonium acetate in PEG-400. The reaction was carried out at 110°С and the products were obtained in good to high yields.
Microwave-assisted three component cyclocondensation reactions of aldehydes, amides and dienophiles in the presence of acetic anhydride and para-toluenesulfonic acid as a catalyst to afford the highly substituted cyclohexene derivatives, in relatively good yields after several minutes are reported.
Several new 2-pyridyl-4-thiazolidinones are synthesized in an efficient manner evading using any catalyst or base. Simple workup procedure, good yields, and mild reaction conditions are the salient features of this method. All the synthesized compounds are screened for antimicrobial activity against several organisms.
cellulose bonded n-propyl diethylene tetra sulfamic acid (cbpdetsa) was successfully applied as a green and recyclable acidic catalyst for the synthesis of tetrahydrobenzo [a] xanthene-11-one as an important class of potentially bioactive compounds. the products are obtained by the coupling of 2-naphtol , cyclohexadione and aldehyde derivatives in good to high yields (70- 92%) under solvent-fre...
An efficient and expeditious catalyst-free procedure was developed for the one- pot synthesis of 1, 4-dihydropyridine derivatives via the three-component reaction of various aldehydes, ethyl acetoacetate, and ammonium acetate in PEG-400. The reaction was carried out at 110°С and the products were obtained in good to high yields.
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