A Comprehensive Review on the Therapeutic Applications and Synthetic Approaches of Buparvaquone

Buparvaquone 1a is a predominant anti-protozoal drug, it belongs to the pharmacologically active class of hydroxy-naphthoquinones. There are numerous publications on the wide therapeutic applications of 1a, but only a few approaches were reported towards its synthesis. Most of the prior arts report the synthesis from expensive raw materials with low yield, whereas only a few involves the use of readily available and less expensive raw materials with moderate to better yield. The present review work covers the developments on therapeutic applications of 1a along with the synthetic approaches disclosed till date

A Systematic Study towards the Synthesis, Isolation, and Recrystallization of Atovaquone, an Antimalarial Drug: A Sustainable Synthetic Pathway

In the present work, studies were conducted towards the synthesis of 2-[trans-4-(4-chlorophenyl) cyclohexyl]-3-hydroxy-1 ,4-naphthoquinone 5 with systematic reaction and recrystallization condition optimization to isolate 5 in high yield with better purity. Synthesis of 5 was done by the hydrolysis of 2-[trans-4-(4-chlorophenyl) cyclohexyl]-3-chloro-1, 4-naphthoquinone 4, which was isolated by the decarboxylative condensation of trans-4-(4-chlorophenyl) cyclohexanecarboxylic acid 3 with naphthoquinone moiety. After the hydrolysis of 4, isolation of crude 5 was done by the use of acetic acid instead of dilute hydrochloric acid, product 5 was isolated in good purity with very less polar impurities. The study extends to provide the polymorphic form I of 5 by the useof solvent combination for the recrystallization, prior artreports the use of a large volume of solvent for theisolation of polymorphic form I of 5. The use of a largevolume of solvent becomes a bottleneck for thecommercial synthesis of 5

A Novel and Sustainable Method for the Synthesis of 2-chloro-3-[trans-4-(4-chlorophenyl) cyclohexyl]-1,4-naphthoquinone, accomplished by systematic process development studies - Trans-Cl synthesis

Present work reports a novel and commercially viable method for the synthesis of 2-chloro-3-[trans-4-(4-chlorophenyl) cyclohexyl]-1,4-naphthoquinone 1, a renowned intermediate of Atovaquone (an antimalarial drug). Majority of the prior arts disclose the synthesis of this intermediate from the expensive starting material 2-chloro-1,4-naphthoquinone 2, in relatively low yield. In this regard, it was considered worthwhile to synthesize 1 by a novel route using cheaper starting material 2,3-dichloro-1,4-naphtoquinone 5, in high yield and purity. In the present study, emphasis was given for selecting the reagents and solvents, optimizing the reaction conditions, recovery and reuse of solvents and silver salt. This optimized novel process is cost effective and would generate less effluent. &nbsp