Abstract: Process for the preparation of compounds of the formula (I): ##STR1## and pharmaceutically acceptable salts thereof wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 which may be the same or different, represent hydrogen, halogen, nitro, lower alkyl or lower alkoxy, where lower means of up to six carbon atoms, or any adjacent two of R.sub.1 to R.sub.4 taken together represent an alkylene group containing from 3 to 5 carbon atoms or a 1,4-buta-1,3-dienylene group, by removal of CH.sub.2 R.sub.5 wherein R.sub.5 is phenyl optionally substituted with one or two groups selected from C.sub.1-4 alkyl, C.sub.1-4 alkoxy, halogen or nitro from a compound of formula (II): ##STR2## with an alkali metal C.sub.1-4 primary alkoxide. The compounds are used to inhibit allergic responses.

Abstract: Compounds of formula (I): ##STR1## wherein R is hydrogen, halogen, C.sub.1-4 alkyl or C.sub.1-4 alkoxy; R.sub.1 is hydrogen or C.sub.1-6 alkyl; and n is 1 to 6 and pharmaceutically acceptable salts thereof; pharmaceutical compositions containing them; a process for their preparation; and their use in treating allergy.