PURPOSE: To obtain a compound useful as a synthetic intermediate, etc., for medicines, agrichemicals, etc., in good yield by subjecting a coal tar-based quinoline to hydrogenating reaction in the presence of a base metallic hydrogenating catalyst and then subjecting the resultant hydrogenated compound to isomerizing reaction in the presence of a noble metallic catalyst.
CONSTITUTION: A coal tar-based quinoline is subjected to hydrogenating reaction in the presence of a base metallic hydrogenating catalyst (e.g. stabilized nickel) at 100-300°C under ≥10kg/cm2G hydrogen pressure to provide a hydrogenation reactional product containing 1,2,3,4-tetrahydroquinoline. The resultant product is further subjected to isomerizing reaction in the presence of a noble metallic catalyst (e.g. Pd supported on active carbon) at 200-300°C in an atmosphere of hydrogen to afford the subject compound. The objective substance is obtained by suppressing the formation of by-products which are difficult to distill and separate without requiring the purification of the coal tar-based quinoline which is the raw material and the hydrogenation reactional product. Decahydroquinoline and quinoline which are readily separable by-products can be recovered from the isomerizing reactional product and then added to the next isomerizing reaction to eliminate the new formation thereof.
SATO TOSHIO
TOKITA MICHIO
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