Synthesis Of Adamantane Polyhydric Alcohols And Novel Adamantane-containing Surfactants

As a new kind of surfactant, Bolaform surfactant has attracted many researchers’ attention. Bolaform surfactant showed lower capacity in decreasing surface tension and higher water solubility than Gemini surfactant when both of them have the same hydrophilic groups and hydrophobic group under room temperature. However, the monolayer lipid membrane (MLM) and monolayer vesicle formed by Bolaform surfactant are of superior thermal stability and special physical-chemical performance, these are its prominent advantages.Adamantane is a cage-shaped saturated hydrocarbon with high symmetry and rigid ring system. It is one of the most approximately spherical hydrocarbons in known compounds, with many special properties, like high lipophilic property, high thermal stability and good lubricous property. In this work, two kinds of new surfactants have been designed and synthesized. The cage-shaped structure of adamantane was designed to be the core connecting surfactant’s hydrophobic groups. The phenyl with high lipophilic property and flexible straight chain hydrocarbon was used as hydrophobic group. The sodium sulfonate with strong surface activity was used as hydrophilic group. The main contents and conclusions are as follows:Adamantane polyhydric alcohols, such as adamantane-1,3-diol, adamantane-1,3,5-triol and adamantane-1,3,5,4-tetraol were successfully synthesized via oxidation of adamantane by using Cr(VI) oxides as oxidation reagents. The synthetic technologies of the three adamantane polyhydric alcohols were investigated and optimized respectively. For adamantane-1,3-diol synthesis:acetic acid as solvent and slight amount H2SO4was used as catalyst, dropping saturated chromic acid(4equiv) at55℃, then reacting at80℃for2h, and the yield was71%. For adamantane-1,3,5-triol synthesis:acetic acid was used as solvent, and slight amount H2SO4as catalyst, dropping saturated chromic acid(8equiv) at55℃, then reacting at80℃for3h, and the yield was42%. For adamantan-1,3,5,7-tetraol synthesis: acetic acid and acetic anhydride was used as solvent with amount H2SO4as catalyst, adding solid CrO3(12equiv) slowly at30℃, then reacting at80℃for2h, and the yield was35%. Such kind of synthetic route has advantages of brief reaction steps, convenient manipulation, mild conditions and so on.1,3-bis(4-hydroxyphenyl)adamantane was successfully synthesized via bromination and alkylation from adamantane. Subsequently, N,N-dimethylformamide was used as solvent,1,3-bis(4-(2-ethoxyl sodium sulfonate)-phenyl)adamantane was synthesized by Williamson condensation reaction from1,3-bis(4-hydroxyphenyl)adamantane and sulfoalkylation reagents in alkaline condition. The highest yield of target product was90%. The structures of products were characterized by elemental analysis, melting points,1H NMR and IR measurements and the surface tensions in different concentrations were tested.Adamantane-1,3,5-triol was synthesized via oxidation of the raw material adamantane. Subsequently,1,3,5-tri(4-hydroxyphenyl)adamantane was successfully synthesized via catal-ytic alkylation from adamantan-1,3,5-triol and phenol in the presence of p-methyl benzenesulfonic acid for72hours. New synthetic route for1,3,5-tri(4-hydroxy phenyl) adamantane was explored:1,3,5-tribromoadamantane was synthesized via bromination of adamantane, thereafter1,3,5-tri(4-hydroxyphenyl)adamantane was successfully synthesized via catalytic alkylation from1,3,5-tribromoadamantane and phenol in the presence of aluminium chloride for24hours. The highest yield of target product was70%.