Cyclopropylacetylene (CA) is a key intermediate in the synthesis for the HIV reverse transcriptase inhibitor Efavirenz, an antiviral drug used to treat HIV. CA is an expensive raw material, difficult to obtain, employed in the preparation of medicaments to combat AIDS. The efficient process for the preparation of CA is described, in which cyclopropyl methyl ketone is chlorinated with PCl5. The resulting 1,1-dichloro-1-cyclopropylethane is isolated and then dehydrochlorinated with potassium tert-butoxide in toluene to form CA. However, the chlorination protocol has been found to take place with appreciable cyclopropyl ring opening. Since, the current methods of synthesizing CA involve ring opening, a new proposal has been made for the change of a different hydrocarbon ring structure. Instead of using a cyclopropyl ring, a larger ring with more than three carbons can result in less ring strain; therefore, less ring opening. Previous experiments have tested out other ring structures; however, they were not hydrocarbons and contained other chemical elements. Efforts toward the synthesis of higher order analogs including cyclobutylacetlylene and cyclopentylaceytlene will be discussed. Various reaction paramitters will be included.

Synthesis of various structural analogs of efavirenz

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