Biobutanol
has a high energy density, good miscibility with gasoline,
and a low environmental impact; therefore, it is a possible substitute
or additive for gasoline. Because biobutanol is typically obtained
through so-called ABE fermentation, the effective separation of butanol
from the product mixture is important. Ionic liquids (ILs) have been
used as extractants, and tailoring the IL structure to promote hydrogen
bonding with butanol could improve the extraction performance. In
the present work, an amine group was added to the imidazole cation
of an IL, paired with bis(trifluoromethylsulfonyl)imide as the anion.
Hydroxyl groups were added to the 1,8-diazabicyclo-[5.4.0]-undec-7-ene
cation, and an imidazolium-based IL was produced by combining hydroxyl
with imidazole. The structures of these three ILs were verified by 1H nuclear magnetic resonance and Fourier transform infrared
spectroscopic analyses. The binding energies between these substances
and butanol, acetone, and ethanol were calculated using the Gaussian
software package based on density functional theory. The results indicated
that the interaction energies between N,N-bis(2-hydroxypropyl)octan-1-aminium hydroxide imidazole ([C8DIPA][Im]) and butanol, acetone, and ethanol are greater than
that with water. These ILs were examined as extractants for the separation
of butanol, acetone, or ethanol with water, and the [C8DIPA][Im] exhibited the best performance. Effects of extraction time,
extraction temperature, and IL proportion on extraction rate were
assessed, and this IL extracted 78%, 34%, and 6% of the three components,
respectively. This performance remained stable after 10 recycling
trials, and [C8DIPA][Im] was also used to separate the
products in an actual ABE fermentation mixture.
Based on a foregoing gram-scale laboratory process, an efficient scale-up preparation process of 5,2′-dibromo-2,4′,5′-trihydroxydiphenylmethanone (LM49-API), a new acute pyelonephritis candidate drug, was developed and validated aiming to reduce by-products and achieve better impurity profiles. Meanwhile, the polymorph of LM49-API and process-related impurities were also investigated. Ultimately, the optimal reaction conditions were verified by evaluating the impurity profiles and their formation during the synthesis. Six process-related impurities were synthesized and identified, being useful for the quality control of LM49-API. Its finalized preparation process was further validated at 329–410 g scale-up production in 53.4–57.1% overall yield with 99.95–99.98% high-performance liquid chromatography (HPLC) purity, and it is currently viable for commercial production. LM49-API-imC and LM49-API-imX were identified as the main single impurities in LM49-API, with the content controlled to be less than 0.03%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.