FIELD : medicine; pharmaceuticals.SUBSTANCE : invention refers to using the compound of formula (I) or its pharmaceutically acceptable salt or tautomer as PPP1R15A inhibitor. In formula (I) R1 means OC1-12alkyl, Cl, F or Br; R2H or F; R3 is H; R4 is H; R5 means H; or R4 and R5 are combined to form 5–6-member saturated or unsaturated heterocyclic group, optionally containing 1 or 2 heteroatoms, such as N, in addition to those N atoms to which R4 and R5, wherein said heterocyclic group is optionally substituted with one or more groups R10; each R10 is independently selected from =O and C1-12alkyl; X and Z each independently denotes CR11, and Y is selected from CR11 and N; R11 means H or C1-12alkyl. Invention also relates to use of compound of formula (I) or its pharmaceutically acceptable salt or tautomer, where R1 means Cl, F or Br; R2 H or F; R3 is H; R4 is H; R5 means H; or R4 and R5 are combined to form 5–6-member saturated or unsaturated heterocyclic group, optionally containing 1 or 2 heteroatoms, such as N, in addition to those N atoms to which R4 and R5, wherein said heterocyclic group is optionally substituted with one or more groups R10; each R10 is independently selected from C1-12alkyl; X and Z each independently denotes CR11, and Y is selected from CR11 and N; R11 means H.EFFECT : treating a disease associated with exposure to mis-stacking of proteins, particularly accumulation of misfolded proteins, and selected from a group of leukodystrophies.13 cl, 14 dwg, 1 tbl, 16 ex