ethyl icosapentate (MND2119 / MND 2119 / icosapent, Mochida)

Update to RIFM fragrance ingredient safety assessment, ethyl (e)hex-3-enoate, CAS Registry Number 26553-46-8.

Api A M AM, Bartlett A A, Belsito D D, Botelho D D et al.

Ethyl (E)hex-3-enoate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, photoirritation/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog methyl 3-hexenoate (CAS # 2396-78-3) show that ethyl (E)hex-3-enoate is not expected to be genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material, and the exposure to ethyl (E)hex-3-enoate is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). Data from read-across analog methyl undec-10-enoate​ (CAS # 111-81-9) show that there are no safety concerns for ethyl (E)hex-3-enoate for skin sensitization under the current declared levels of use. The photoirritation/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; ethyl (E)hex-3-enoate is not expected to be photoirritating/photoallergenic. The environmental endpoints were evaluated; ethyl (E)hex-3-enoate was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotient (RQ), based on its current volume of use (VoU) in Japan (JP) (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), is <1. Ethyl (E)hex-3-enoate could not be risk screened for Europe (EU), North America (NA), Asia-Pacific (AP), or South America (SA), as there were no reported VoUs for these regions in the 2023 IFRA Survey.

Update to RIFM fragrance ingredient safety assessment, ethyl isovalerate, CAS Registry Number 108-64-5.

Api A M AM, Bartlett A A, Belsito D D, Botelho D D et al.

Direct Conversion of Methyl-Ethyl-Ketone into Olefins Precursors of Fuels and Chemicals over Supported Cu Catalysts.

Shi Hanzhong H, He Yang Y, Dagle Vanessa Lebarbier VL

As global demand for light olefins continues to increase, driven by expanding plastics production and the need for jet fuel precursors, biomass-derived oxygenates such as methyl-ethyl-ketone (MEK) have emerged as promising intermediates for olefin production. This study investigates the selective hydrodeoxygenation of MEK to butene over copper catalysts supported on Al2O3, SiO2, and SiO2-Al2O3, each offering distinct acid characteristics. Among the catalysts evaluated, 10Cu/SiO2-Al2O3 achieved the highest olefin selectivity (97.6%) while maintaining a high MEK conversion level (>80%) due to its acidity and favorable metal-support interactions. Further studies revealed that at temperatures above 210 °C, the reaction pathway progressively shifts from hydrodeoxygenation toward aldol-condensation, producing undesired carboxylic acids and ketones, while simultaneously accelerating deactivation through hard-coke formation. A scaled-up experiment using a 100 g catalyst batch demonstrated that 10Cu/SiO2-Al2O3 operated at 210 °C (1 atm, w8 h space velocity = 0.8 h-1, PMEK = 12%) sustains high conversion (∼90%) and olefin selectivity (94-97%) for more than 140 h, with full recovery of activity and selectivity after mild oxidative regeneration. These results establish 10Cu/SiO2-Al2O3 as a robust and scalable catalyst for MEK hydrodeoxygenation, offering mechanistic insight into activity, selectivity, and deactivation pathways critical for industrial implementation.

Four polymorphic structures of a symmetric azo dye.

Hill Max T MT, Birch-Machin Mark A MA, Sellars Jonathan D JD, Waddell Paul G PG

The synthesis and structural characterisation of a symmetric azo dye, ethyl azocinnamate, via single crystal X-ray diffraction led to the discovery of four polymorphic forms. The crystals and their structures were analysed in terms of morphology, conformation, intermolecular interactions and overall crystal packing. This analysis provides insight into their properties, formation and stability. Two distinct conformations were observed, with two representative structures of each. The structures are layered, and were observed to grow as flat, planar crystals with the exception of one, the prismatic habit of which could be attributed to the strong inter-layer interactions unique to this form. The elastic properties of one of the polymorphs was linked to columns of π⋯π interactions along one direction, a feature absent in the more rigid forms. One polymorph with Z' > 1, which crystallises in the space group P21, is analysed in terms of approximate symmetry and is found to be a distorted P21/c structure.