1409957-10-3

Upstream product

• 1409956-67-7 cis/trans-2-(4-(4-chlorophenyl)cyclohexyl)-3,4-dihydronaphthalen-1(2H)-one 
• 1409956-62-2 2-(4-(4-chlorophenyl)cyclohex-1-en-1-yl)-3,4-dihydronaphthalen-1(2H)-one 
• 25253-51-4 4-(4-chlorophenyl)cyclohexanone monoehtylene ketal 
• 126991-60-4 4-(4-chlorophenyl)cyclohex-3-enone monoehtylene ketal 
• 1409956-99-5 cis/trans-2-(4-(4-chlorophenyl)cyclohexyl)naphthalen-1-ol 
• 1409956-84-8 cis/trans-2-bromo-2-(4-(4-chlorophenyl)cyclohexyl)-3,4-dihydronaphthalen-1(2H)-one 
• 126991-59-1 8-(4-chlorophenyl)-1,4-dioxaspiro[4.5]decan-8-ol 
• 106-39-8 bromochlorobenzene 
• 14472-80-1 4-(4-chlorophenyl)cyclohexan-1-one 
• 4746-97-8 cyclohexanedione monoethylene ketal 

Downstream Products

• 1203609-10-2 cis-2-[4-(4-chlorophenyl)cyclohexyl]-1,4-naphthoquinone 
• 1409957-42-1 cis-1a-(4-(4-chlorophenyl)cyclohexyl)naphtho[2,3-b]oxirene-2,7(1aH,7aH)dione 

Relevant academic research and scientific papers

IMPROVED SYNTHESIS OF 2-(4-(4-CHLOROPHENYL) CYCLOHEX-1-ENYL) -3, 4-DIHYDRONAPHTHALEN-1 (2H)-ONE; AN INTERMEDIATE FOR ATOVAQUONE

A process for preparation of 2-(4-(4-chlorophenyl) cyclohex-l-enyl)-3,4-dihydronaphthalen- 1(2H)-one (V), key intermediate for synthesis of Atovaquone [I]. The process for preparation of compound(V) comprising of the steps of; i) Reaction of 2-(4-(4-chlorophenyl)-1-hydroxycyclohexyl)-3,4-dihydronaphthalen- 1(2H)-one (IV) with trifluro acetic anhydride in presence of base in organic solvent to yield compound of formula (XIa) ii) Elimination of trifluoroacetyl functionality of compound (XIa) in organic solvent and in presence of organic base to give compound of formula (V). The invention also provides a Process for preparation of compound(XIa) comprising of the steps of; i) reaction of 2-(4-(4-chlorophenyl)-l-hydroxy cyclohexyl)-3,4-dihydronaphthalen- 1(2H)-one (IV) with trifluro acetic anhydride in presence of organic base in organic solvent. A further process is provided for preparation of compound(V) from compound (XIa) comprising elimination reaction of trifluoroacetyl functionality compound (XIa) in organic solvent and in presence of organic base.

NOVEL METHOD FOR PREPARATION OF ATOVAQUONE

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.