反应详情

The 5-, 6-, 7- and 8-hydroxycarbostyrils used for the preparation of the starting material used in the present invention are described in Berichte, Vol. 20, page 2172, 1887; Journal of Organic Chemistry, Vol. 36, pp 3490-3493, 1971 and ibid, Vol. 33, pp 1089-1092, 1968. Briefly, 5-hydroxycarbostyril can be prepared by fusing 5-hydroxyquinoline with a caustic alkali such as sodium hydroxide or potassium hydroxide, and 8-hydroxycarbostyril can be prepared by reacting 8-hydroxyquinoline with hydrogen peroxide in glacial acetic acid to produce 8-hydroxyquinoline 1-oxide which is then refluxed in acetic anhydride to obtain acetoxycarbostyril and hydrolyzing the resulting acetoxycarbostyril with concentrated hydrochloric acid to give the desired 8-hydroxycarbostyril. The 6- and 7-hydroxycarbostyrils can be prepared in a similar manner to those described above.

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