4-(Methylsulfonyl)benzaldehyde → (Z)-5-methoxy-2-methyl-1-(p-methylsulfonylbenzylidene)-3-indenylacetic acid

참여 물질

반응 단계

25% methanolic sodium methoxide (16 ml, 2.0 equivalents) is treated with a solution of methyl 5-methoxy-2-methyl-3-indenylacetate (from Example 4, Part C) (8.7 g; 0.037 mol) and p-methylsulfonylbenzaldehyde, (6.3 g; 1.1 equivalent). The mixture is stirred at reflux under nitrogen for 2 hours. An equal volume of water is added slowly, and refluxing is continued for 30 min. The solution is cooled, is diluted with water and is washed with ether. Residual ether is blown off with nitrogen. The aqueous solution is acidified with 10% hydrochloric acid. The precipitated product is collected and is washed thoroughly with water. The crude product is crystallized from methanol to give (Z)-5-methoxy-2-methyl-1-(p-methylsulfonylbenzylidene)-3-indenylacetic acid.

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