Abstract: A compound of formula (I) wherein R1, R2, R3, R4, X, Y, and A are as defined herein. The compounds of the present invention are inhibitors of hematopoletic prostaglandin D synthase (H-PGDS) and can be useful in the treatment of Duchenne muscular dystrophy. Accordingly, the invention is further directed to pharmaceutical compositions comprising a compound of the invention. The invention is still further directed to methods of inhibiting H-PGDS activity and treatment of disorders associated therewith using a compound of the invention or a pharmaceutical composition comprising a compound of the invention.