| 摘要 |
Title compds. (I; R = H, C1-12 alkyl or C2-5 alkanoyloxy or -NR4R5 substituted C1-12 alkyl; R4,R5 = H or C1-10 alkyl; R1 = C2-4 alkyl or C3-4 alkenyl; R2 = H; R3 = not substituted or methyl substituted furyl, thienyl or pyridyl; n = 0 or 1) useful as an asthmatic, hay fecer, were manufd. by the reaction of II and III. Thus, 64g methyl 3-valeroyl-4-hydroxybenzoate was refluxed with 138ml anhydrous acetic acid for 4 hr in 30ml triethylamine to give 69.2g 6-carbomethoxy-3-propyl-2-methyl-chromone, which was treated with 600 ml KtH solution to give 28g 6-carboxy-3-propyl-2-trans-styryl-chromone.
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