5435-44-9

Upstream product

• 141-97-9 ethyl acetoacetate 
• 57-13-6 urea 
• 75-44-5 phosgene 
• 7732-18-5 water 
• 76-03-9 trichloroacetic acid 

Downstream Products

• 123237-03-6 ethyl 6-methyl-4-phenyl-3,4-dihydropyrimidin-2(1H)-one-5-carboxylate 
• 4141-43-9 DL-O¹,O⁶-dibenzoyl-O²,O³;O⁴,O⁵-((RS,RS)-dibenzylidene)-galactitol 
• 94-49-5 1,2-ethanediol, dibenzoate 
• 939-55-9 2-chloroethyl benzoate 
• 91427-49-5 2-(2-chloroethoxy)ethyl benzoate 
• 110-56-5 1,4-dichlorobutane 
• 110-52-1 1,4-dibromo-butane 
• 7239-41-0 4,4'-dibromo-di-n-butyl ether 
• 115-11-7 isobutene 
• 628-67-1 butane-1,4-diol diacetate 
• 946-02-1 4-chlorobutyl benzoate 
• 6962-92-1 4-Chlorobutyl acetate 
• 75-07-0 acetaldehyde 
• 106-35-4 heptan-3-one 

Relevant academic research and scientific papers

Antimony(III) chloride-catalysed Biginelli reaction: a versatile method for the synthesis of dihydropyrimidinones through a different reaction mechanism

Antimony(III) chloride (20 mol %) in refluxing acetonitrile efficiently catalyses the synthesis of dihydropyrimidinones (50-90% yields) by the Biginelli reaction of aromatic aldehydes, acetoacetate esters and urea. This reaction proceeds through 3-ureido-crotonates followed by cyclisation with an aromatic aldehyde to the dihydropyrimidinone.

Iodine-catalyzed synthesis of β-uramino crotonic esters as well as oxidative esterification of carboxylic acids in choline chloride/urea: a desirable alternative to organic solvents

Abstract: Iodine-mediated selective synthesis of β-uramino crotonic esters was achieved via the reaction of β-dicarbonyls and urea at room temperature. Choline chloride/urea mixture, as an eco-friendly, cheap, non-toxic, and recyclable deep eutectic solvent (DES), was employed as sustainable media as well as reagent at the same time in these transformations. Some derivatives of β-uramino crotonic esters were synthesized with good to high yields without a tedious work-up. The process could be done to synthesize the above-mentioned compounds in gram scale. Moreover, oxidative cross-esterification of carboxylic acids with alkyl benzenes was carried out in the above-mentioned DES by the employment of tetrabutylammonium iodide (TBAI) as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant at 80?°C. DES/TBAI system was reused up to five consecutive times. Graphic abstract: Iodine-catalyzed C–N and C–O bond formation in choline chloride/urea as a green solvent under the mild reaction conditions. Providing the clean procedure toward synthesis of β-uramino crotonic esters and benzylic esters.[Figure not available: see fulltext.].

Highly Efficient Synthesis of Substituted 3,4-Dihydropyrimidin-2-(1H)-ones (DHPMs) Catalyzed by Hf(OTf)4: Mechanistic insights into reaction pathways under metal Lewis acid catalysis and solvent-free conditions

In our studies on the catalytic activity of Group IVB transition metal Lewis acids, Hf(OTf)4 was identified as a highly potent catalyst for”one-pot, three-component” Biginelli reaction. More importantly, it was found that solvent-free conditions, in contrast to solvent-based conditions, could dramatically promote the Hf(OTf)4-catalyzed formation of 3,4-dihydro-pyrimidin-2-(1H)-ones. To provide a mechanistic explanation, we closely examined the catalytic effects of Hf(OTf)4 on all three potential reaction pathways in both “sequential bimolecular condensations” and “one-pot, three-component” manners. The experimental results showed that the synergistic effects of solvent-free conditions and Hf(OTf)4 catalysis not only drastically accelerate Biginelli reaction by enhancing the imine route and activating the enamine route but also avoid the formation of Knoevenagel adduct, which may lead to an undesired byproduct. In addition, 1H-MMR tracing of the H-D exchange reaction of methyl acetoacetate in MeOH-d4 indicated that Hf(IV) cation may significantly accelerate ketone-enol tautomerization and activate the β-ketone moiety, thereby contributing to the overall reaction rate.