The development of an effective synthetic route of lesinurad (RDEA594)

Discovery of Novel Bicyclic Imidazolopyridine-Containing Human Urate Transporter 1 Inhibitors as Hypouricemic Drug Candidates with Improved Efficacy and Favorable Druggability

Lesinurad is a uricosuric agent for the treatment of hyperuricemia associated with gout, which was found lacking in efficacy and safety. Here, scaffold hopping and molecular hybridization were exploited to modify all the structural components of lesinurad, and 36 novel compounds bearing bicyclic imidazolopyridine core were obtained. In a mouse model of acute hyperuricemia, 29 compounds demonstrated increased serum uric acid (SUA)-reducing activity; SUA was treated with 12, 23, and 29 about fourfold lower compared with that of lesinurad. Moreover, 23 exhibited stronger URAT1 inhibition activity (IC₅₀ = 1.36 μM) than lesinurad (IC₅₀ = 5.54 μM). Additionally, 23 showed favorable safety profiles, and no obvious acute toxicity was observed in Kunming mice under a single dose of 1000 mg·kg^-1. 23 also achieved excellent pharmacokinetic properties with the oral bioavailability of 59.3%. Overall, all the results indicated that 23 is a promising drug candidate in the treatment of hyperuricemia and gout.

Efficient Pd-Catalyzed Direct Coupling of Aryl Chlorides with Alkyllithium Reagents

Organolithium compounds are amongst the most important organometallic reagents and frequently used in difficult metallation reactions. However, their direct use in the formation of C-C bonds is less established. Although remarkable advances in the coupling of aryllithium compounds have been achieved, Csp2 -Csp3 coupling reactions are very limited. Herein, we report the first general protocol for the coupling or aryl chlorides with alkyllithium reagents. Palladium catalysts based on ylide-substituted phosphines (YPhos) were found to be excellently suited for this transformation giving high selectivities at room temperature with a variety of aryl chlorides without the need for an additional transmetallation reagent. This is demonstrated in gram-scale synthesis including building blocks for materials chemistry and pharmaceutical industry. Furthermore, the direct coupling of aryllithiums as well as Grignard reagents with aryl chlorides was also easily accomplished at room temperature.

Novel Human Urate Transporter 1 Inhibitors as Hypouricemic Drug Candidates with Favorable Druggability

Lesinurad, a human urate transporter 1 (URAT1) inhibitor approved as a medication for the treatment of hyperuricemia associated with gout in 2015, can cause liver and renal toxicity. Here, we modified all three structural components of lesinurad by applying scaffold hopping, bioisosterism, and substituent-decorating strategies. In a mouse model of acute hyperuricemia, 21 of the synthesized compounds showed increased serum uric acid (SUA)-reducing activity; SUA was about 4-fold lower in animals treated with 44, 54, and 83 compared with lesinurad or benzbromarone. In the URAT1 inhibition assay, 44 was over 8-fold more potent than lesinurad (IC₅₀: 1.57 μM vs 13.21 μM). Notably, 83 also displayed potent inhibitory activity (IC₅₀ = 31.73 μM) against GLUT9. Furthermore, we also preliminarily explored the effect of chirality on the potency of the promising derivatives 44 and 54. Compounds 44, 54, and 83 showed favorable drug-like pharmacokinetics and appear to be promising candidates for the treatment of hyperuricemia and gout.

Evolution of flow-oriented design strategies in the continuous preparation of pharmaceuticals

This review focuses on the flow-oriented design (FOD) in the multi-step continuous-flow synthesis of active pharmaceutical ingredients.