21405-59-4

Upstream product

• 141-82-2 malonic acid 
• 104-87-0 4-methyl-benzaldehyde 
• 203861-67-0 N-methyl-4-tolylnitrone 

Downstream Products

• 1866-39-3 trans-p-methylcinnamic acid 
• 68208-18-4 3-amino-3-(p-tolyl)propionic acid 

Relevant academic research and scientific papers

Synthesis of a new urea derivative: A dual-functional organocatalyst for Knoevenagel condensation in water

A phenylalanine-urea compound-catalyzed Knoevenagel condensation in water is reported. Various aldehydes and active methylene compounds undergo condensation at room temperature to give the desired products in high yields. The mechanism of the condensation of aldehydes with Meldrum's acid catalyzed by the novel urea derivative is also disclosed.

Solvent-dependent reactivities of acyclic nitrones with β-diketones: Catalyst-free syntheses of endiones and enones

Reactions of the nitrones -O+N(Me)C(H)Ar 1 (Ar=phenyl 1a, 4-methylphenyl 1b, 2,4,6-trimethylphenyl 1c, and anthracen-9-yl 1d) with the cyclic β-diketones 1,3-indandione 2 or barbituric acid 3 in CH 2Cl2, afford the corresponding endiones 2′a-2′d or 3′a-3′d. In contrast, dimedone 4 reacts with 1a or 1b to give the endione 4′a or 4′b and the bis-adduct 4″a or 4″b. Nevertheless, reaction of 4 with 1c or 1d in CH 2Cl2 furnishes only the endione adducts 4′c or 4′d. However, the reaction of 4 with 1a or 1b in methanol gives only 4″a or 4″b, respectively. Among acyclic β-diketones only malonic acid 7 reacts with 1a-1c. Reaction of 7 with 1a in CH2Cl 2 forms cinnamic acid 7″a, whereas in the case of 1b, the endione 7′b and (E)-3-p-tolylacrylic acid 7″b are obtained. The nitrone 1c reacts with 7 in CH2Cl2 to afford the endione 7′c or with acetone yielding (E)-4-mesitylbut-3-en-2-one 8. X-ray analyses are reported for 4′c, 5, and 7″b. In addition, the calculated acidity of the hydrogen at the α-C atom is shown to correlate with the reactivity of the β-diketones with nitrones.

Effect of microwave irradiation on reaction of arylaldehyde derivatives with some active methylene compounds in aqueous media

The effect of microwave irradiation on the condensation reactions of arylaldehydes 1 and active methylene compounds 2 in aqueous media was studied and compared with "classical" conditions. The results show that the condensation was carried out only under microwave irradiation in the presence of ammonium chloride as a catalyst, followed by dehydration, to afford (E)-olefins 3. The protocol was used to synthesize coumarins by a condensation reaction of salicylaldehyde or its derivatives with various derivatives of ethylacetate 5 (e.g., R3CH2CO2Et; R3: CO 2Et, CO2Me, COMe, CN) in high yields. These investigations will contribute to the development of environmentally friendly and inexpensive processes in organic synthesis.

A one-pot synthesis of 3-amino-3-arylpropionic acids

3-Aminopropionic acids (β-amino acids) are biologically active compounds of interest in medicinal and pharmaceutical chemistry. Twenty-one 3-amino-3-arylpropionic acids were synthesized via a facile one-pot synthesis. In addition, a series of mechanistic studies have been performed to optimize the production of these β-amino acids. The reaction mechanism of this one-pot synthesis of β-amino acids, as well as the electronic effect of para-substitution and the influence of solvent polarity on the proposed reaction mechanism are discussed.

Solvent-free bentonite-catalyzed condensation of malonic acid and aromatic aldehydes under microwave irradiation

Solvent-free condensation between malonic acid and aromatic aldehydes in the presence of bentonite was investigated. Various diacids were obtained in good to moderate yields and in very short short reaction times under microwave irradiation. The method showed simplicity in performance, non-aqueous work-up, no side products and low cost.

Microwave enhanced Knoevenagel condensation of malonic acid on basic alumina

An improved Knoevenagel condensation of malonic acid and aldehydes can be achieved by microwave irradiation over alumina. A number of diacids were prepared in good yields in very short reaction times.