单氨基改性PBO的AB型新单体的合成

Synthesis of new AB monomers of amino modified PBO

研究了以4-(甲氧羰基)-2-硝基苯甲酸(β-MNT)与4-氨基-6-硝基间苯二酚盐酸盐(ANR·HCl)为原料经酰氯化、N-酰化、环合、水解和催化加氢还原等一系列反应合成得到中间体4-((2,4-二羟基-5-硝基)氨甲酰基)-3-硝基苯甲酸甲酯(3-NMNC)、4-(5-硝基-6-羟基-2-苯并唑基)-3-硝基苯甲酸甲酯(3-NMNB)、4-(5-硝基-6-羟基-2-苯并唑基)-3-硝基苯甲酸(3-NNBA)及单氨基改性PBO的AB型新单体4-(5-氨基-6-羟基-2-苯并唑基)-3-氨基苯甲酸(3-AABA),并对环合、水解和催化还原加氢的反应条件进行了优化。结果表明:对于环合反应,以二乙二醇二甲醚为溶剂,PPA为环合脱水剂其中P2O5含量84%,w(PPA)∶w(3-NMNC)=9.5∶1,反应温度140℃,反应时间8h,3-NMNB收率73.16%,HPLC纯度99.10%;水解反应,以乙醇与水为溶剂,n(K2CO3)∶n(3-NMNB)=1.8∶1,加热水解2h,3-NNBA收率74.19%,HPLC纯度为98.59%;催化加氢还原反应,甲醇为溶剂,w(10%Pd/C):w(3-NNBA)=1∶20,1 MPa氢压,80℃反应5h得3-AABA,HPLC纯度99.43%,收率65.08%。中间体和产物结构经FT-IR、13C-NMR和ESI-MS表征确认。

Using 4-methoxycarbonyl-2-nitro-benzoic acid（β-MNT） and 4-amino-6- nitroresorcinolhydrochloride（ANR·HCl） as the starting materials, we synthesized the intermediates 4-（5-nitro-6-hydroxybenzoxazole-2-yl）-3-nitro-methyl benzoate（3-NMNC）, 4-（5-nitro-6-hydroxybenzoxazole-2-yl）-3-nitrobenzoate（3-NMNB）, 4-（5-nitro-6-hydroxy benzoxazole-2-yl）-3-aminobenzoic acid（3-NNBA） and the final product 4-（5-amino-6-hydroxy benzoxazole-2-yl）-3-aminobenzoic acid（3-AABA） through a series of reaction,including acylchloride,N-acylation,cyclization,hydrolysis and catalytichydrogenation reduction reaction. The optimal cyclization, hydrolysis and catalytichydrogenation reduction conditions were obtained. The experimental results for the cyclization reaction showed that taking diethyleneglycol dimethyl ether as solvent,the polyphosphoric acid（PPA） as dehydrant and the content of P2O5 in PPA of 84%,w（3-NMNC）∶w（PPA）=1∶9.5,the reaction temperature of 140℃ and the reaction time of 8h,we obtained the yield of 3-NMNB of 73.16% and its purity was 99.10% as determined by HPLC. The experimental results for the hydrolysis reactionshowed that using ethanol and water as solvent,n（K2CO3）∶n（3-NMNB） = 1.8：1 and the reaction time of 2h,we got the yield of 3-NNBA of 74.19% and the purity was 98.59% as determined by HPLC. The experimental results for the hydrogenation reduction reaction showed that using methanol as solvent,w（10%Pd/C）∶w（3-NNBA）=1∶20,pressure of hydrogen of 1.0 MPa,reaction temperature of 80℃,reaction time of 5h,we had the yield of 3-AABA of 65.08% based on 3-NNBA and the purity was 99.43% as determined by HPLC.