ES363112A1 - A procedure for preparing benzodipirons. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

A procedure for preparing benzodipyrones of formula I: **(See formula)** in which one or more adjacent pairs of P, Q, R and T form the chain -CO-CR1 = C (COOH) -O-, which can be attached to the benzene ring in either direction; and the rest of P, Q, R and t, which may be the same or different, are hydrogen, or a substituent other than hydrogen, and are preferably hydrogen, halogen, hydroxyl, nitro, lower alcohol, lower alkenyl, lower alkoxy, lower alkenyloxy., aralkoxy, lower alkoxy, lower alcohol, or a heterocyclic ring, both R 1 can be the same or different and are alcohol, substituted alcohol, or alkoxy groups containing 1 to 10 carbon atoms, aryl groups, or preferably hydrogen, comprising cyclizing, preferably under acidic conditions, a compound of the formula: **(See formula)** in which B1, B2, B3 and B4 have the same meaning as P, Q, R and T above, except that one or more adjacent pairs of B1, B2, B3 and B4 may represent the group pair -COCHR1COCOR'' and -OM; M is hydrogen, an alkali metal atom or an alcohol group, and R'' is an -OH group or a group, preferably a -O-alcohol group, which can be converted to an -OH group, and R1 is as follows defined above. (Machine-translation by Google Translate, not legally binding)