| 摘要 |
Process for preparing indanones and thioindanones, especially 5-chloroindanone and 5,6-dimethoxyindanone, in a 2-stage process, comprises: (1) acylation, in the presence of HF and optionally BF3, of a (substituted) benzene (I) to add a side chain of at least 3 C atoms and with carbonyl or thiocarbonyl group alpha to the benzene ring; and (2) cyclization of the product in the presence of sulfuric acid. Process for preparing indanones and thioindanones, especially 5-chloroindanone and 5,6-dimethoxyindanone, in a 2-stage process, comprises: (1) acylation, in the presence of HF and optionally BF3, of a (substituted) benzene of formula (I) to add a side chain of at least 3 C atoms and with carbonyl or thiocarbonyl group alpha to the benzene ring; and (2) cyclization of the product in the presence of sulfuric acid. R = H, halogen, pseudohalogen, or an electron-donor, or two groups R may form a 5 or 6-membered carbocycle or heterocycle; and n = 0 - 4, preferably 1 or 2 The acylating agent is preferably of formula Z'-C(=Y')-R5 (II) Y' = O or S; R5 = -C(R1)(R2)-C(R3)(R4)-X; R1 - R4 = H or 1-6C alkyl; X = halogen; Z = halogen, -O-C(O)-R5, or -OR'; and R' = 1-6C alkyl. T The preparation of 3,4'-dichloropropiophenone and 3-chloro-3',4'-dimethoxypropiophenone is especially preferred. The reaction mixture may distilled to eliminate, at least partially, the HF and BF3 and, without further purification, is treated with 95 - 99.9% sulfuric acid in the molar ratio 1 : 1 - 30, especially 1 : 5 - 20, and heated at 30 - 120 (preferably 80 - 100 deg C) to effect cyclization and give (IV) |
