نتایج جستجو برای: solvent free conditions
تعداد نتایج: 1355934 فیلتر نتایج به سال:
one-pot synthesis of pyrrole derivatives via reaction between activated carbonyl compounds, primary amines and 1,3-dicarbonyls under solvent-free conditions is described.
2-amino-substituted ketones react with α-methylene ketones under solvent-free conditions at 90 °c in thepresence of a catalytic amount of zirconium dodecylphosphonate to create the corresponding quinolinesin excellent yields. this procedure recommends numerous advantages such as easy work-up, use of mild,reusable and safe catalyst, short reaction timeand high yields. the new compounds have been...
for the first time lactic acid was applied as an efficient and green catalyst for the one-pot three-component synthesis of amidoalkyl naphthols via the condensation between arylaldehydes, 2-naphthol and amides or urea under thermal solvent-free conditions in good to excellent yields. we have demonestrated a mild and efficient eco-friendly tandem synthesis of amidoalkyl naphthols using lactic ac...
Methoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of 1,3-dichloro-5,5-dimethyl hydantoin [DCDMH] and Poly N,N′-dibromo-N-ethyl naphthyl-2,7-disulfonamide [PBNS] as catalysts at room temperature and under solvent-free conditions. Our experiments show that primary and secondary alcohols can be smoothly converted into the corresponding MOM...
A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...
An efficient synthesis of Methyl 2-[2-(alkylimino)-4-oxo-3-phenyl-1,3-thiazolan-5-yliden]acetate derivatives via simple three-component reaction and one-pot reactions between isoquinoline, dimethyl acetylenedicarboxylate and N-phenylthiourea under solvent-free conditions without using any additional catalyst, is described. The mild reaction conditions and good yields and exhibit the synthetic a...
Quinazolinone derivatives are nowadays well recognized as valuable scaffold in drug discovery. In this manuscript an improved multicomponent process for the chemical synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives is described. Isatoic anhydride and aromatic aldehydes with ammonium acetate have been subjected to a three-component reaction under solvent-free conditions and catalysis of ...
A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...
-a simple, efficient, and general method has been developed for the chemoselective acetalization of aldehydes with 1,3-propanediol, 1,2-ethanediol and trimethyl orthoformate in the presence of solid lithium perchlorate under solvent-free conditions. both cyclic and acyclic acetals of aldehydes were obtained under environmentally benign conditions in good to excellent yields.
Palladium-catalyzed addition of disulfides and diselenides to alkynes under solvent free conditions.
An efficient methodology was developed for performing palladium-catalyzed E-E (E = S, Se) bond addition to alkynes under solvent free conditions. Compared to reaction in solvent significant enhancement of reaction rate, improved efficiency and remarkable catalyst stability were observed under solvent free conditions. The addition reactions were carried out with high stereoselectivity and yields...
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