NEW MATERIAL:Carboxylic derivatives of formula I (A is O, S; R1 is H, methyl; R2 is hydroxyl, amino) and their nontoxic salts.

EXAMPLE: 2-[10,11-Dihydro-11-hydroxybenz(b,f)apin-2-yl]propioic acid.

USE: They have anti-inflammatory activity and are used as anti-inflammatory. They may orally or non-orally be administered.

PREPARATION: The reduction of a compound of formula II is effected in an organic solvent as alcohol or ether using a reducing reagent as sodium borohydride to give the compound of formula I. The nontoxic salt is, e.g., a metal salt of sodium or calcium or amine salt.