Study On The Synthesis Of Ginkgolic Acids And The Analogues Of Ginkgolic Phenols

Ginkgolic phenols/acids and their analogues possess insecticidal activities, antibacterialactivities, and the antibacterial spectrum is also broad. The task focuses on the studies ofsynthetic methods for ginkgolic acids and several analogues of ginkgolic phenols, meanwhilethe synthetic technological conditions for the analogues of ginkgolic phenols were alsoinvestigated. The results are as follows:1. o-Hydroxybutyrophenone (o-HBP) was prepared by Fries rearrangement of phenylbutyrate (PB) in the presence of AlCl₃-PhNO₂. The influence of the catalyst amount, reactiontemperature and time on the yield of o-HBP was discussed by orthogonal test andsingle-factor test. The results showed that the PB was completely converted, and the yield ofo-HBP was 36ï¼…when n(AlCl₃):n(PB)=1: (1～1.2), reaction temperature and time was 120℃, 2hours respectively.2. o-Allyl phenol (AP) was prepared with allyl chloride and phenol as raw materials, viaO-alkylation, Claisen rearrangement. The influence of several typical solvents and bases onthe yield of allyl phenyl ether (APE) was studied. Further, the effect of some factors, such asthe mole ratio of raw materials, reaction temperature and reaction time, on the yield of APEwas investigated. The experiment results showed that the reaction activity of phenol could beimproved in the presence of sodium hydroxide with methanol as a solvent, and the optimizedconditions were as follows: the mole ratio of phenol to allyl chloride was 1:1.2, reactiontemperature was 60℃, and reaction time was 4h. Under the conditions above, the yield ofAPE was 65.0ï¼…. AP was obtained via reflux of APE under the temperature of 190～220℃for7h with the yield of 81.2ï¼….3. Synthetic conditions for acyl/alkyl phenols, the analogues of ginkgolic phenols, wereinvestigated, via the C-acylation and C-alkylation of aromatic ring from phenol, catechol,resorcinol, and hydroquinone with butyryl chloride, dodecanoyl chloride as acylation reagents,n-octanol as alkylation reagent in the presence of anhydrous aluminium chloride or sulfuricacid. Finally butyryl catechol, butyryl resorcinol, butyryl hydroquinone, dodecanoyl phenol and octyl phenol were prepared.4. Synthetic methods for ginkgolic acids were investigated based on the analytical studyto the literature, i.e. the synthetic route for hydroginkgolinic acid was studied with 2,6-dimethoxy benzoic acid and n-bromotetradecyl magnesium as the starting materials, viaacylation, condensation, chlorination, cyclization, C-nucleophilic substitution of aromatic ringand hydrolysis. Acylation reaction, condensation reaction and chlorination reaction in thesynthetic route were well elucidated, and TLC determination methods for the synthetic routewere established.