Synthesis of industrial chemicals from cardanol and anacardic acid components of cashew nut shell liquid

Anacardic acid and cardanol, components of Cashew Nut Shell Liquid, have been employed to synthesize various chemicals of industrial importance. Metathesis of cardanol with symmetrical alkenes was employed to synthesize short chain derivatives of cardanol. These derivatives were methoxycarbonylated using a highly efficient and selective 1,2-bis(di-tert-butylphosphinomethyl)benzene (DTBPMB) modified palladium catalyst to produce bifunctional monomers with different chain lengths such as C9-COOMe, C10-COOMe, C11-COOMe, C12-COOMe and C15-COOMe. Polymerization of the synthesized monomers produced oligomers that consist of up to seven monomer units as confirmed by MALDI-TOF-MS. Lactone formation was also observed in some cases under polymerization conditions. Hydrogenation of C15-COOMe monomer in the presence of Triphos, ruthenium and hydrogen produced an aminophenol and hydroxyphenol. Polymerization of the hydroxyphenol and the aminophenol with dimethyl nonadecanedioate produced oligomers with improved flexibility. Ethoxylation of C9-COOMe and C15-COOMe monomers followed by polymerization of the synthesized ethoxylates produced gummy like and plastic like oligomers respectively. Isomerisation of monoene anacardic acid using DTBPMB modified palladium catalyst, followed by decarboxylation and metathesis of the formed isoanacardic acid produced 3-propyl phenol in 18 % yield. Apart from bifunctional monomers synthesized, industrial useful alkenes such as 1-octene, (E)-non-2-ene, (E)-dec-3-ene, (E)-undec-4-ene and (E)-hexadec-2-ene were obtained as side products from metathesis reactions of cardanol and its derivatives reported in this study.