| 摘要 |
1439990 Condensed benzopyran derivatives and pharmaceutical uses thereof BOEHRINGER INGELHEIM GmbH 28 Aug 1973 [29 Aug 1972] 40417/73 Heading C2C The invention comprises compounds of formula (wherein R 1 represents a hydrogen atom or a (C 1-4 ) alkyl group; R 2 , R 4 , R 5 which may be the same or different, each represents a hydrogen or halogen atom or a (C 1-4 ) alkyl, hydroxy, (C 1-4 ) alkoxy, (C 2-5 ) acyloxy, nitro or -SO 3 H group; and R 3 and R 6 , which may be the same or different, each represents a hydrogen or halogen atom or a (C 1-4 ) alkyl, hydroxy, (C 1-4 ) alkoxy, (C 2-5 ) acyloxy, nitro, hydroxycarbonylmethoxy, #-hydroxyethoxy, #-aminoethoxy or -SO 3 H group) and salts thereof. These compounds may be obtained by treating a compound of formula (wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are as defined above) with an oxalic acid ester, e.g. diethyloxalate. These compounds may also be obtained by cyclizing a compound of formula in the presence of a strong mineral acid such as H 2 SO 4 The starting material of Formula II may be obtained by (a) a Fries arrangement of the ester of formula The ester of Formula (2) is obtained by treating a phenol of formula with acetic anhydride in the presence of AlCl 3 . The phenols of Formula I may be obtained by treating a lactone of formula with diborane boron trifluoride (when R 1 represents hydrogen); or with Grignard alkylating reagent (when R 1 represents an alkyl group) The intermediates of Formula III may be obtained by reacting the phenol of Formula (1) with dimethylacetylene dicarbonic acid in a basic medium, (for detailed methods see Example 2). The invention also relates to a pharmaceutical composition comprising at least one compound of Formula I or a physiologically compatible salt thereof in association with a pharmaceutical carrier. These compositions are reported to have antiallergic properties and may be suitable nasal, topical, parenteral or enteral administration. |
