| dc.description.abstract | Even though carbon-11 has some very interesting features for PET imaging, its potential has still not been fully exploited. Reasons for this could be that its short half-life requires an efficient and fast synthesis route, or that its primary synthons are quite unreactive, limiting its chemistry. However, great engineering work has been done, and carbon-11 chemistry is on the rise, moving towards novel methods aside from the main strategy, [11C]-methylation. Previously, Flumazenil, a selective GABAA receptor antagonist, has been radiolabeled in different positions with the aim to perform nuclear imaging of GABAA receptors in the brain. Due to metabolites, the best candidate is [11C]-methylated Flumazenil. However, for research purposes, it could be interesting to radiolabel Flumazenil in the carbonyl position, giving a possibility to learn more about Flumazenil and its metabolite in the brain, while also performing novel carbon- 11 chemistry and developing precursor synthesis routes that also can be adaptable to- wards other targets. The aim of this study is therefore to synthesize a precursor for Flumazenil that can be radiolabeled in the carbonyl position of the ester group and then to radiolabel it through [11CO]-carbonylation. Another goal of this study is to establish an efficient process for [11C]-methylation of Flumazenil using design of experiments as a tool. In this work, a synthesis strategy for generating precursors that can be radiolabeled in the carbonyl position of an ester group next to heteroatoms on heteroaromatic rings has been developed. Establishment and partly optimization of a process for [11C]-methylation of Flumazenil using design of experiments has been done. | |
