18516-18-2Relevant articles and documents
Method for synthesizing BDO by using 2 - device byproduct 2 hydroxymethyl propionaldehyde and 2 -dimethylolpropionic acid
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Paragraph 0014; 0051-0053; 0054-0056; 0057-0059; 0060; ..., (2021/09/08)
The invention provides a method for producing BDO by using 2 - byproduct 2 hydroxymethyl propanal, in particular: 2 - hydroxymethyl propanal is condensed under the action of an alkali catalyst, and formaldehyde is condensed to obtain 2 - and 2 dimethylolpropionic aldehyde intermediate which is catalytically oxidized to obtain 2 - and 2 2 - dimethylolpropionic acid. The synthetic route is novel, and by-product BDO hydroxymethyl propanal produced in 2 - process by allyl alcohol method is a starting material and is condensed. 2, 2 Dimethylolpropionic acid is obtained through the oxidation and the like to obtain 2 - and the byproduct of the waste is comprehensively utilized, BDO device three wastes are reduced, a new product can be sold, and the economical efficiency of the device is effectively improved.
Self- and cross-aldol condensation of propanal catalyzed by anion-exchange resins in aqueous media
Pyo, Sang-Hyun,Hedstroem, Martin,Hatti-Kaul, Rajni,Lundmark, Stefan,Rehnberg, Nicola
experimental part, p. 631 - 637 (2011/12/02)
Carbon-carbon bond formation using strong and weak anion-exchange resins as green catalysts for self- and cross-aldol condensation of propanal in aqueous media was investigated. The reaction pathway followed the route of aldol condensation to a β-hydroxy aldehyde and dehydration to an α,β-unsaturated aldehyde. The resulting products were further converted to hemi-acetal, and/or acetal moieties, which were confirmed by FT-IR and NMR. In self-condensation using strong anion-exchange resin, 97% conversion of propanal was achieved with 95% selectivity to 2-methyl-2-pentenal within 1 h using 0.4 g/mL resin at 35 °C. The conversion and selectivity using weak anion exchanger was lower. During cross-aldol condensation of propanal with formaldehyde, 3-hydroxy-2-methyl-2-hydroxymethylpropanal was obtained as the main product through first and second cross-condensation followed by hydration reaction in acidic aqueous conditions. The strong anion-exchange resin provided maximal propanal conversion of 80.4% to the product with 72.4% selectivity after 7 h reaction at 35 °C and resin concentration of 1.2 g/mL. Using weak anion-exchange resin, the optimal conversion of propanal was 89.9% after 24 h at 0.8 g/mL resin and 35 °C, and the main product was 3-hydroxy-2- methylpropanal by first cross-aldol condensation along with relatively minor amounts of methacrolein and 3-hydroxy-2-methyl-2-hydroxymethylpropanal.
