PURPOSE: To economically separate and recover quinoline in high yield and high purity by two-step distillation of an absorptive oil containing indole, quinoline, methylnaphthalene etc. followed by acid cleaning.
CONSTITUTION: An absorptive oil of coal tar origin containing at least indole, quinoline and methylnaphthalene is distilled at a normal pressure-reduced temperature of ca.250°C and separated into a fraction containing most of both the quinoline and methylnaphthalene and the residual liquor containing most of the indole. Thence, the former fraction is distilled at a normal pressure reduced overhead temperature of 230-240°C and pref. at ≥30 in theoretical number of row and ≥3 in reflux ratio and separated into the residual liquor containing most of 1-methylnaphthalene and a fraction containing most of both the quinoline and 2-methylnaphthalene. Said fraction is then put to acid cleaning, thus recovering the quinoline in the form of its salt.
TACHIBANA YAKUDO
TAKIGAWA YASUYUKI
ONO MASAMI
UEDA TORATARO
FUJIMURA KATSUNORI
HASEBE SHINJI
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