Synthesis of 6-isomer of 5,8-O-dimethyl ether of shikonin (13), a promising anticancer scaffold, always remains a huge challenge. Herein a key intermediate for 13, 2-(1-hydroxyl-4-methyl-3-pentenyl)-1,4,5,8-tetramethoxynaphthalene (10), was obtained on the large-scale synthesis. A ring-closing/ring-opening strategy was applied to avoid the undesired reactivity posed by the side chain and racemi...

Artificial neural networks (ANNs) are designed and implemented to model the direct synthesis of dimethyl ether (DME) from syngas over a commercial catalyst system. The predictive power ANNs is assessed by comparison with predictions lumped parameterized fit same data used for ANN training. training converges much faster than parameter estimation model, show higher degree accuracy under all cond...

The conversion of waste and residues towards high added value products has receiving a growing attention, as reliable strategy to improve sustainability emergent processes. Anaerobic digestion converts organic into biogas digestate. While may be used for energetic purpose, digestate limited uses with low profitability. In this paper, dimethyl ether (DME) is adopted target product which produced...

Embryonic X-ray amorphous semi-formed MFI-type zeolite units mixed with the Cu–Zn–Al catalyst have been used for direct synthesis of dimethyl ether (DME) from syngas. The hybrid embryonic (EZ) particle size 5 nm has demonstrated superior performance in terms activity, selectivity, and stability compared to crystalline ZSM-5 counterpart aluminosilicate material. FTIR pyridine adsorption uncovere...

Abstract Oxymethylene ethers (OME) are an attractive alternative to fossil diesel fuel due strongly reduced harmful emissions. An anhydrous, liquid phase production process based on dimethyl ether (DME) has been elaborated, which offers high selectivity and economic advantages. A catalyst screening for the reaction of DME with trioxane carried out. Highly active catalysts could be identified fu...

In this work the continuous production of dimethyl ether (DME) by sorption-enhanced DME synthesis (SEDMES) technology has been demonstrated for first time with a multi-column test-rig. A single-pass carbon yield up to 95%, higher than ever reported before, achieved. The experiments have also shown that SEDMES can be operated at lower temperatures (220°C) previously reported. This allows tempera...