Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, York, UK.
Magn Reson Chem. 2021 Dec;59(12):1187-1198. doi: 10.1002/mrc.5152. Epub 2021 Apr 5.
Utility of the pyridazine motif is growing in popularity as pharmaceutical and agrochemical agents. The detection and structural characterisation of such materials is therefore imperative for the successful development of new products. Signal amplification by reversible exchange (SABRE) offers a route to dramatically improve the sensitivity of magnetic resonance methods, and we apply it here to the rapid and cost-effective hyperpolarisation of substituted pyridazines. The 33 substrates investigated cover a range of steric and electronic properties and their capacity to perform highly effective SABRE is assessed. We find the method to be tolerant to a broad range of electron donating and withdrawing groups; however, good sensitivity is evident when steric bulk is added to the 3- and 6-positions of the pyridazine ring. We optimise the method by reference to a disubstituted ester that yields signal gains of >9000-fold at 9.4 T (>28% spin polarisation).
嘧啶基作为医药和农用化学品的应用越来越受到关注。因此，为了成功开发新产品，对这些材料进行检测和结构特征分析是至关重要的。通过可逆交换进行信号放大（SABRE）为显著提高磁共振方法的灵敏度提供了一种途径，我们在此将其应用于取代嘧啶的快速、经济高效的超极化。研究的 33 种底物涵盖了一系列的空间和电子性质，并评估了它们进行高效 SABRE 的能力。我们发现该方法对广泛的供电子和吸电子基团具有耐受性；然而，当嘧啶环的 3-和 6-位增加空间位阻时，灵敏度明显提高。我们通过参考二取代酯进行了方法优化，在 9.4 T（>28%自旋极化）下，信号增益超过 9000 倍（>28%自旋极化）。
