| 摘要 |
PURPOSE:To obtain the titled compound useful as expectorants, etc. in high yield advantageously, by passing a raw material through various improved seps including the Fries rearrangement or the Hoesch reaction using 2,4,6-trihydroxy-3,5- dimethyl-benzene as an intermediate. CONSTITUTION:(a) A compound of formulaIobtained by the nitrating step of m-dimethylbenzene in two stages or the reducing step with iron powder in place of part or all of the tin without using an alcohol and the hydrolytic step under ordinary pressure is reacted with coumaric acid, particularly an alkoxycarbonylcoumaryl halide, at a high temperature, and subjected to the Fries rearrangement and reduced or (b) the compound of formulaIis acetylated with acetonitrile and hydrogen chloride in the presence of zinc chloride to give a compound of formula II, which is then condensed and cyclized preferably in glycerol solvent in the presence of p-hydroxybenzaldehyde and boric acid to afford the aimed compound of formula III. |
