1203609-11-3

Upstream product

• 1010-60-2 2-chloro-1,4-naphthoquinone 
• 95233-37-7 (+/-)-trans-4-(4-chlorophenyl)cyclohexane carboxylic acid 
• 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

• 1409957-21-6 cis/trans-1a-(4-(4-chlorophenyl)cyclohexyl)naphtho[2,3-b]oxyrene-2,7(1aH,7aH)-dione 

Relevant academic research and scientific papers

A single-pot synthesis of atovaquone: An antiparasitic drug of choice

The present article relates to a practical, economically viable, and validated at industrial scale, single-pot synthetic route for preparation of atovaquone, one of the most versatile antiparasitic drugs of choice used for the prophylaxis and treatment of diseases such as pneumocystis, toxoplasmosis, babesiosis, coccidiosis, and malaria. However, owing to the extremely poor yields of synthesis and very high doses of treatment (due to poor bioavailability) the cost of treatment with this drug is not affordable by the patients in need, particularly in the third world countries where these diseases are most prevalent. Unlike most of the reported processes which use 2-chloronaphthoquinone and pure trans-4-chlorophenyl cyclohexane carboxylic acid, our process is based on the decarboxylative alkylation of isomeric mixture of 4-chlorophenyl cyclohexane carboxylic acid with 1,4-naphthoquinone to give 42% overall yield of atovaquone, 10 times higher than from the reported process (4%) from the innovators of this drug.

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.

A novel process for synthesis of atovaquone

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

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.