| 摘要 |
NEW MATERIAL:The indole-2,7-dicarboxylic acid compound of formula I (R1 and R2 are H or lower alkyl). EXAMPLE:Indole-2,7-dicarboxylic acid 2-methly-7-ethyl diester. USE:Useful as an intermediate for the synthesis of photo-sensitive materials, pharmaceuticals, and agricultural chemicals. For example, the selective decarbonation of the 2-carboxylic acid group of indole-2,7-dicarboxylic acid gives indole- 7-carboxylic acid useful as a photo-sensitive material of instant photography, raw material of pharmaceuticals, etc. PREPARATION:The compound of formula I can be prepared by reacting anthranilic acid or its ester of formula II with sodium nitrite in the presence of concentrated hydrochloric acid, reacting the reaction product with a liquid obtained by adding potassium hydroxide to an alcoholic solution of 2-methylacetoacetic acid ester, and hydrolyzing the resultant compound of formula III after cyclization.
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