Synthesis And Resolution Of1,1’-Bina Phthalene-2’2’-Dithiol

1,1’-binaphthalene-2,2’-dithiol was a typical chiral compound,which has a strong surface asymmetry. It could be splitted into enantiomer easily and the purity of the enantiomer was very high.So1,1’-binaphthalene-2,2’-dithiol was a very usefully compoud in the synthesis of organic,dyes,pesticides and specialty pharmaceutical industries.This paper discussed the process of synthesizing and resolving1,1’-binapht halene-2,2’-dithiol.1,1’-binaphthalene-2,2’-dithiol was sythesized by2-naphthol,which was the raw material.This part should through the oxidative coupling reaction,Sn2nucleophilic substitution reaction,Newman-Kwart rearrangement reaction and the reduction reaction to synthsize1,1’-binaphthalene-2,2’-dithiol.1,1’-binaphthalene-2,2’-diol was synthesized by oxidative coupling reaction,ratio of raw materials,oxidant,temperature and other factors were studied by orthogonal experiment and single factors experiment,the yield(purity)was94.6%(98.4%).1,1’-binaphthalene-2,2’-diylO,O-bis(N,N-dimethylthiocarbamate) was syntyesized by SN2nucleophilic substitution reaction,ratio of mate rial, solvent and temperature were studied.And the best ratio of material was n(1,1’-binaphthalene-2,2’-diol):n(KOH):n(N,N-dimethlthiocarbamoyl)=1:2:2.2.The yield (purity)was93.4%(98.9%).For Newman-Kwart rearrangement reaction, the most important condition of rearrangement reaction was the temperature.The reaction was heated to270℃for40min,and it must be under the protection of N2.What’s more,the material must be recrystallized before the reaction.The yield(purity)was86.5%(98.6%).The conditions of reduction reaction including the reducing agent,the ratio of raw materials and solvents.The optimized reduction reactions were as follows:the ratio of raw materials was n(1,1’-binaphthalene-2,2’-diylS,S-bis(N,N-dimethylthiocarbamate) :n(lithium aluminum hydride)=1:1, the temperature of reaction was65℃and the time was2h.The yield of1,1’-binaphthalene-2,2’-dithiol was89.4%and the purity was99.3%.The second step was the resolution of1,1’-binaphthalene-2,2’-diol.The (S)-(-)-α-methylbenzylamine was the resolving agent.The preferred raw material ratio was n(thiophosphoryl):n((S)-(-)-α-methylbenzylamine):n(1,1’-binaphthalene-2,2’-diol)=1:1:0.95.And the yield was83.0%.The best reaction conditions of synthesizing (S)-1,1’-binaphthalene-2,2’-diol was as follows:the reaction should be protected by N2and reacting at0℃for2h with the lithium aluminum hydride.The yield(purity) was72.1%(98.3%).The purity of all products and intemediates were detemined by HPLC,structures confirmed by1H NMR、IR、GC-MS.