57711-74-7

Upstream product

• 100-52-7 benzaldehyde 
• 802294-64-0 propionic acid 
• 538-51-2 benzylidene phenylamine 
• 7424-54-6 3,5-heptanedione 

Downstream Products

• 1609547-31-0 1-(2-ethyl-4-phenyl-4,5-dihydrofuran-3-yl)propan-1-one 

Relevant academic research and scientific papers

Efficient solvent-free knoevenagel condensation between -diketone and aldehyde catalyzed by silica sulfuric acid

Silica sulfuric acid has been utilized as an efficient heterogeneous recyclable catalyst for Knoevenagel condensation between poorly reactive β-diketones and aldehydes under solvent-free conditions. This protocol also works well with more reactive β-ketoesters. The condensation is efficient, clean, and mild. The scope and generality of the Knoevenagel condensation were investigated. The procedure led only to the Knoevenagel product, and no side product derived from a subsequent Michael βaddition of -diketone to alkene was detected at rt. Increasing temperature led to a subsequent Michael addition, and it was applied to the efficient synthesis of 9-aryl-1,8-dioxo- octahydroxanthene derivatives.

A new route to 2-alkenyl-1,3-dicarbonyl compounds, intermediates in the synthesis of dihydrofurans

A two step synthetic strategy for obtaining 2-alkenyl-1,3-dicarbonyl compounds from the corresponding 1,3-dicarbonyl compounds is reported. The method is based on a Knoevenagel condensation and a Michael addition using a high order organocuprate procedure, and proves to be of general value. Obtained compounds are useful starting materials for the synthesis of furan derivatives.

Kinetics of Amine Addition to Benzylidene-1,3-indandione and Other Vinylic β-Diketones. Effect of Cyclic Structure and Steric Strain on Intrinsic Rate Constants

The kinetics of the reactions of benzylidene-1,3-indandione (4) with piperidine, morpholine, n-butylamine, 2-methoxyethylamine, glycinamide, and cyanomethylamine and the reactions of benzylidene-3,5-heptanedione (5), benzylidene-2,6-dimethyl-3,5-heptanedione (6), and benzylidenedibenzoylmethane (7) with piperidine and morpholine have been measured in 50% Me2SO-50% water (v/v) at 20 °C and 0.5 M ionic strength. The reactions lead, in all cases, to the reversible formation of the zwitterionic adduct PhCH(RR′NH+)C(COX)2- (TA±) that is in fast equilibrium with its anion PhCH(RR′N)C-(COX)2-(TA-). Rate constants for nucleophilic addition (k1) and its reverse (k-1) as well as the pKa, of TA± were determined for all reactions. The intrinsic rate constant (k0 = k1 = k-1 when K1 = 1) for amine addition to 4 is abnormally high, whereas k0 for the reactions of 5-7 are abnormally low and similar to k0 in magnitude for amine addition to benzylideneacetylacetone reported previously. The terms "abnormally high" and "abnormally low" refer to positive and negative deviations, respectively, from a plot of log k0 for amine addition to a series of electrophilic olefins of the type PhCH=CYY′ vs log k0 for deprotonation of carbon acids of the type CH2YY′. The high k0 for the reaction of 4 is attributed to its cyclic structure, which assures that the π-overlap required for the stabilization of the adduct is strongly developed in the transition state. The low k0 values for the reactions of 5-7 arise from intramolecular hydrogen bonding, which is strong in TA± but poorly developed in the transition state, and from steric strain in the adduct, which is strongly developed in the transition state. All these effects can be viewed as manifestations of the principle of nonperfect synchronization (PNS).

Catalyst compositions for trimerizing organic isocyanates

Disclosed are novel compositions capable of catalytically trimerizing organic isocyanates said compositions comprising solutions of the reaction products obtained by reacting in an inert solvent in substantially equimolar proportions electron-rich ketene-aminals with electron-poor olefins having the respective formulae (I) and (II) STR1 The variously substituted electron-rich ketene-aminals (I), as the name implies, have high electron density associated with the double bond because of the two tertiary amine groups while the electron-poor olefins (II) have the opposite situation due to the presence of electron withdrawing substituents R9 and R10. Also disclosed is an improved process for trimerizing organic isocyanates using the above catalyst compositions including the preparation of polyisocyanurate polymers and isocyanurate-modified polyisocyanates.