3-异烷氧基噻吩的合成

以CuB r为催化剂,NMP为溶剂,在110℃下,3-溴噻吩与过量的甲醇钠反应2.5 h生成3-甲氧基噻吩,产率为82%。再以无水NaHSO4为催化剂,在108~115℃下,3-甲氧基噻吩分别与异丁醇、异戊醇、异辛醇发生取代反应合成了3-(2-甲基丙氧基)噻吩、3-(3-甲基丁氧基)噻吩、3-(2-乙基己氧基)噻吩,反应时间分别为:3、3.5、4h,收率分别为72%、67%、63%。这些化合物结构都通过IR、1HNMR和MS进行了表征,并对其进行了初步香味评价,结果表明,它们都具有基本肉香味的特征。

Synthesis of 3-Isoalkoxythiophene

With cuprous bromide as catalyst and N-methylpyrrolidone(NMP) as solvent,3-bromothiophene reacted with surplus sodium methoxide at 110 ℃ for 2.5 h to form 3-methoxythiophene in 82% yield.Then 3-(2-methylpropoxy) thiophene,3-(3-methylbutoxy)thiophene and 3-(2-ethylhexoxy)thiophene were respectively synthesized through substitution reaction of 3-methoxythiophene with isobutanol,isopentanol and isooctanol using sodium bisulfate as catalyst at 108~115 ℃.The reaction times were 3,3.5 and 4 h and the yields were 72%,67% and 63% respectively.The products were confirmed by IR,~1HNMR and MS.Their flavour was evaluated and it is shown that they all have basic meat flavour.