Preparation and Synthesis of Mono-bridged Carbazolopyridinophane Intermediates
Abstract
Hydrazine is a toxic compound commonly used in rocketry, pesticides, and pharmaceuticals. The severity of hydrazine exposure requires sensors to enforce safety requirements. Traditional methods are irreversible and hindered by response time and sensitivity. Carbazolopyridinophane (CP) was synthesized by the Brown group as a reusable carbazole-based sensor offering real-time detection at thresholds of 100 ppb. With the recommended threshold at 10 ppb, there remains a need for a sensor with a lower detection limit. As part of the ongoing effort on CP, this work explores amono-bridged CP to fill the target threshold. However, the synthesis was hindered by an Åkermark cyclization with low conversion resulting in difficulties isolating the target compound from its precursor. This was remedied with prep TLC, alleviating a constricting step in the overall synthesis using an approachable method which yields high purity and highly reproducible results.