Sarah Swartwout, “Synthesis and Biological Evaluation of Novel Benzodiazepines for the Potential Oral Treatment of Asthma”
Mentor: Alexander Arnold, Chemistry & Biochemistry
Poster #170

MIDD0301 is a novel anti-inflammatory asthma drug candidate that targets gamma amino butyric acid type A receptors (GABAAR) without causing systematic immune suppression. In developing a comprehensive structure activity relationship, the use of a novel synthetic strategy involving various amino acid N-carboxyanhydrides (NCAs) has proven to enable a route towards the synthesis of disubstituted imidazodiazepines that was not accessible using the reported methods involving peptide coupling reagents. The reaction to synthesize these NCA’s has been extensively optimized for the equivalents of triphosgene, triethylamine, and ethyl acetate required for it to progress to completion. However, the current recrystallization method using 50% dichloromethane in hexanes has not successfully resulted in a pure product for the spiro cyclopropane NCA analog that is used in the synthesis of DAW-III-30. Here, we present several trials to improve the NCA purity through optimization of the recrystallization methods. The NCA was then reacted with a substituted aniline to form a benzodiazepine in good yield. Following this reaction is a two-step process using diethyl chlorophosphate and ethyl isocyanoacetate as well as potassium t-butoxide as a base, which enabled the formation of an imidazodiazepine. Hydrolysis under strong basic conditions yields the desired analog, DAW-III-30, which then was evaluated for its ability to interact with GABAARs and relax airway smooth muscle. DAW-III-30 and intermediates were evaluated by a cytotoxicity assay using human embryonic kidney cells (HEK293). A rotarod test was employed to screen for any adverse CNS effects where the results showed no adverse effects for DAW-III-30. Subsequently, the compound was tested for its ability to attenuate airway hyperresponsiveness using non-invasive airway mechanics where the results showed comparable efficacy to MIDD0301.