1409957-21-6Relevant articles and documents
A novel process for synthesis of atovaquone
Roy, Bhairab N,Singh, Girij P,Lathi, Piyush S,Agrawal, Manoj K,Mitra, Rangan,Trivedi, Anurag
, p. 1299 - 1312 (2014/01/06)
A stereospecific efficient process for synthesis of atovaquone i.e. trans-2-[4-(4-chlorophenyl)cyclohexyl ]-3-hydroxy-1,4-naphthalenedione and its cis isomer from commercially available raw materials such as α-tetralone and 4-(4-chlorophenyl)cyclohexanone
NOVEL METHOD FOR PREPARATION OF ATOVAQUONE
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, (2012/12/13)
Provided is a process of preparation of 2-[trans,-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy- 1,4-naphthoquinone, i.e. Atovaquone [I] which is cost effective, green, and eco-friendly process, without separation of any diastereomers or geometric isomers of intermediates obtained during the reactions. Also provided is separation of 'cis' and 'trans ' isomer of intermediates VI, VII and VIII through selective crystallization in an appropriate solvent. A method for converting 2-[cis,-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy-1,4-naphthoquinone to 2-[trans-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy-l,4-naphthoquinone in presence of Lewis/ Bronsted acid is also provided. A process for preparation of compound 2-(4-(4- chlorophenyl)- 1 -hydroxy cyclohexyl)-3,4-dihydronaphthalen- 1 (2H)-one [IV] comprising condensation of (1,2-dihydronaphthalen-4-yloxy)trimethylsilane [II] with 4-(4- chlorophenyl)cyclohexanone [III] in presence of Lewis acid in organic solvent. The invention also encompasses a highly efficient and atomeconomic process for synthesis of compound [III] i.e. 4-(4-chlorophenyl)cyclohexanone as well as a process for synthesis of 2-[cis-4-(4'- chlorophenyl)cyclohexyl]-3-hydroxy-l,4-naphthoquinone. Further provided is a process for isomerization of cis- Atovaquone i.e. 2-[cis-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy-l,4- naphthoquinone to tnms-Atovaquone i.e. 2-[trans-4-(4'-chlorophenyl)cyclohexyl]-3- hydroxy- 1,4-naphthoquinone in presence of Lewis acid.
