74338-98-0

MS, NMR, IR and Raman molecular spectroscopy techniques were applied to characterize 3-tert-butoxy-propane-1,2-diol, 1,3-di-tert-butoxy-propan-2-ol, and 1,2,3-tri-tert-butoxy-propane. These ethers are the main products of glycerol etherification reaction and are excellent oxygen additives for diesel fuel. Computational DFT/ B3LYP/6-31G** studies were performed to support and rationalize both vibrational spectroscopy analysis and the isomer ratio.

The etherification of glycerol with tert-butyl alcohol has been carried out in the liquid-phase on different sulfonic acid functionalized hybrid silicas obtained by oxidative cleavage of tetrasulfide bridges. These materials exhibited different textural properties and acidities ranging from 0.5 to 2.3?mmol?g?1. First of all, different experimental variables, including the reactant ratio and temperature have been tested and all catalysts were essayed under optimal conditions. The best catalytic behavior of the hybrid silicas was obtained on S50TS50O (Yh-GTBE?=?28%) at 75?°C and autogenous pressure. In fact, the glycerol conversion obtained on S50TS50O, clearly surpassed that obtained on A-15 (74 and 51%, respectively). The acidity and the hydrophilic character of the sulfonated hybrid silicas solids have been found to be key parameters for their catalytic activity whereas the surface area and porosity do not seem to be advantageous for this reaction. All catalysts were reused and subjected to an extensive characterization.

Sulfonated niobia (HY-340 CBMM) and pillared clay (Fluka) were tested in the catalytic conversion of glycerol by etherification reactions. The solids were treated with concentrated fuming sulfuric acid (AS100 and NS100), and a 30% aqueous solution of this acid (AS30 and NS30). Both the presence of sulfur and the increase in the acidity of the solids demonstrate the suitability of the sulfonation process, especially in samples treated with concentrated fuming sulfuric acid. The best catalyst for the reaction of etherification with tert-butyl alcohol was AS100, with a glycerol conversion of 95% after 5 h at 393 K and yield of 60.3, 33.2 and 5.4%, respectively for mono-tert-butyl-glycerol (MTBG), di-tert-butyl-glycerol (DTBG) and tri-tert-butyl-glycerol (TTBG).

We compared the performance of more than 70 solid acid catalysts with Br?nsted acid function for the etherification of glycerol with isobutene under identical reaction conditions of 75 °C, 10 bar, 6 h and with an isobutene/glycerol molar ratio of 3/1. The catalysts were selected from a wide range of solid acid catalysts including ion exchange resins, zeolites, silica, and heteropolyacids, and their counterparts modified by simple treatments, with more than half of them being investigated for the first time for this reaction. For the modified commercial acid catalysts, the desired glycerol tertiary butyl ether (DTBGE and TTBGE) selectivity improved from 75 to 87 wt% upon partial cation exchange of the sulfonic acid protons in Amberlyst type ion exchange resins with Na+ cations; from 66 to 85 wt% by hydrothermal steam treatment of zeolite H-Y (SiO2/Al2O3 = 80); and from 75 to 80 wt% with partial La+-exchange of zeolite H-Beta (SiO2/Al2O3 = 300), all at high (90–100%) glycerol conversion. Impregnation of the heteropolyacids, tungstosilicic acid (TSA) and tungstophosphoric acid (TPA), on silica at a loading of 50 wt% provided a glycerol conversion of higher than 65 wt% and with a desired ether selectivity in the range of 62 to 76 wt%. In general, total ether selectivity increased with decreasing acid capacity for ion exchange resins, while the desired ether selectivity was enhanced with increasing acid strength for zeolites and supported heteropolyacids on mesoporous silica. Data present a detailed guideline for the selection of solid acid catalysts for the etherification of glycerol with isobutene.

The invention discloses a preparation method of 1,3-propanediol, and relates to the technical field of chemical synthesis. According to the scheme, glycerol is used as a raw material to prepare 1,3 propylene glycol by using a functional group directional protection method, that is, a terminal hydroxyl group is selectively protected through an etherification reaction, secondary hydroxyl group is removed through a sulfonylation reaction and a reduction reaction, and a protective group is removed. The process of the preparation method provided by the invention has the characteristics of high yield, few byproducts, low cost, easy separation and the like, is an environment-friendly and economical route, overcomes the defects of complex operation and low yield in the prior art, and has a wide development prospect.

New chiral macrocyclic cobalt(III) salen complexes were synthesized and used as catalyst for the asymmetric kinetic resolution (AKR) of terminal epoxides and glycidyl ethers with aromatic/aliphatic amines and water as nucleophiles. This is the first occasion where a Co(III) salen complex demonstrated its ability to catalyze AKR as well as hydrolytic kinetic resolution (HKR) reactions. Excellent enantiomeric excesses of the epoxides, the corresponding amino alcohols and diols (upto 99%) with quantitative yields were achieved by using the chiral Co(III) salen complexes in dichloromethane at room temperature. This protocol was further extended for the synthesis of two important drug molecules, i.e., (S)-propranolol and (R)-naftopidil. The catalytic system was also explored for the synthesis of chirally pure diols and chiral cyclic carbonates using carbon dioxide as a greener renewable C1 source. The catalyst was recycled for upto 5 catalytic cycles with retention of enantioselectivity. (Figure presented.).

Hierarchical zeolite possessing MFI framework type was hydrothermally prepared using C22H45???N+(CH3)2???C6H12???N+(CH3)2???C6H13 as a structure-directing agent in a seed-assisted synthesis method. The nanosponge-like morphology was composed of a three-dimensional disordered network of MFI layers with 2.5?nm thickness supporting each other. Catalytic performance of the MFI nanosponge was investigated in glycerol etherification with tert-butyl alcohol in liquid phase and compared to conventional microporous MFI zeolite and MFI unilamelar nanosheet. The hierarchical zeolites were much more active, which can be attributed to the acid sites located on the external surfaces accessible for the reaction of bulky reactants.

Glycerol is a major by-product in the biodiesel production process. Every 100 kg of biodiesel produced generates approximately 10 kg of crude glycerol. As the biodiesel industry has expanded rapidly in recent years, finding new uses of the excess crude glycerol is important. Many studies have examined alternative uses of crude glycerol. One of them is the use of glycerol derivatives, such as glycerol tert-butyl ethers as fuel additives. In this paper, the etherification kinetics of glycerol with tert-butyl alcohol to glycerol tert-butyl ethers was studied using an Amberlyst catalyst. The influences of the catalyst type and loading, reaction time, molar ratio, and temperature were investigated in detail.

The present invention relates to a process for the conversion of a feedstock containing one or more fatty acid triglycerides to a mixture containing one or more fatty acid alkyl esters and t-alkyl glycerols, comprising reacting said feedstock with a compound of formula (I): R-O-RI (I) wherein: RI is an alkyl, alkenyl or alkynyl having 1-18 carbon atoms; R is H or a tertiary alkyl group, wherein said reaction takes place in the presence of an acid transesterification catalyst by irradiation with microwaves and/or ultrasound and/or radio waves.

In this work the etherification reaction of glycerol with isobutene (IB) and tert-butyl alcohol (TBA) has been studied with the aim of preparing mixtures with high content of poly-substituted ethers. The results obtained using solid acid catalysts have shown that the reaction with IB proceeds at a high rate but the formation of undesired di-isobutene (DIB) represents a serious problem when catalysts with high density of acid sites, such as Amberlyst, are used. When using TBA as a reactant, the main problem is the formation of water that, due to thermodynamic reasons, prevents the formation of poly-substituted ethers regardless of the catalyst used. Some preliminary experiments carried out with a water permselective tubular membrane have demonstrated that the yield of poly-substituted ethers significantly increases once water was selectively removed from the reaction medium by recirculation of the gas phase. [Figure not available: see fulltext.]

Retention characteristics, temperature dependences of the retention characteristics, and thermodynamic characteristics of sorption on the nonpolar OV-101 phase are determined for 33 glycerol mono-, di-, and triethers with linear and branched monobasic alc