Title: Synthesis of Methyl 4-(5-Nitro-6-hydroxybenzoxazol-2-yl) benzoate
Abstract:The synthesis of methyl 4-(5-nitro-6-hydroxybenzoxazol-2-yl)benzoate(MNB),an AB-type monomer precursor for a new AB-type poly(p-phenylene benzobizoxazole)(PBO)was studied,and the synthesis of MNB from...The synthesis of methyl 4-(5-nitro-6-hydroxybenzoxazol-2-yl)benzoate(MNB),an AB-type monomer precursor for a new AB-type poly(p-phenylene benzobizoxazole)(PBO)was studied,and the synthesis of MNB from 4-amino-6-nitroresorcinol hydrochloride(ANR·HCl)and mono-methyl terephthalate(MTA)was developed by means of acyl chlorination,condensation and cyclization separately or in situ synthesis.The optimum conditions were methyl isobutyl ketone as solvent,feed ratio(mol ratio)of ANR·HCl/MTA of 1.00∶1.03,and condensation reaction at 115 ℃ for 2.5 h.Cyclization reaction at 120 ℃ for 8.5 h after adding PPA as dehydrating agent at a feed ratio(mass ratio)of ANR·HCl/PPA of 1.00∶3.25,the product was obtained with a yield of 75.68% and the purity of MNB without further purification was 96.32% by HPLC method.Structures of the products were characterized by 1H NMR and IR.Read More
Publication Year: 2009
Publication Date: 2009-01-01
Language: en
Type: article
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