3.3 Application in synthetic routes analysis
To study the effectiveness of RSscore in synthetic routes analysis, we
utilized three synthetic routes of paracetamol for validation. As all
three synthetic routes utilize the reaction of p-aminophenol with acetic
acid at the end of paracetamol synthesis routes, its overall impact on
synthetic route is negligible. After obtaining the reaction condense
hypergraph descriptors and calculating the RSscore of each reaction of
the synthetic routes in Fig. 6 , the RSscore for reactions in
route (a) are 0.7430 and 0.5587; the RSscore for reactions in route (b)
are 0.6535 and 0.4492, and the RSscore for reactions in route (c) are
0.7569 and 0.5867, respectively. By comparing the RSscore values of the
reaction in the synthetic routes, the reactions in route (a) and (c)
exhibit better overall performance compared to the route (b). This
demonstrates that synthetic route (a) and (c) are more favorable than
route (b) in terms of the combination of reaction time, yield and
temperature condition.
In practical studies of these synthetic pathways, Route (a) has the
advantages of short reaction time and high yield.49Route (b) requires fewer steps, but the yield for the p-aminophenol
generation is low, while the handling of the waste residue generated is
difficult. Therefore, this synthesis method has been abandoned by many
countries.50 Route (c) could generate a high-quality
of p-aminophenol, and its yield can reach 72%.50Through a comparison of synthetic routes, Routes (a) and Routes (c) are
relatively better and perform little difference on reaction yield, time
and temperature conditions. Although the cost for Route (c) is cheaper
than Route (a), the price factor is not involved in the proposed
indicator, therefore the RSscore is not able to distinguish the
difference between the two routes.