FIELD: chemistry.SUBSTANCE: invention relates to a new compound of formula (I) or a pharmaceutically acceptable salt thereof. Compounds are protein kinase inhibitors and have antiproliferative activity. Compounds can be used to treat, reduce severity or prevent a condition that responds to the inhibition of anaplastic lymphoma kinase. In the compound of formula (I) (I) each R1 is independently selected from hydrogen and C1-10 alkyl, where C1-10 alkyl is unsubstituted or is substituted by at least one substituent independently selected from R6a each R2 is independently selected from C1-10 alkyl and piperidinyl provided that at least one group R2 is piperidinyl, where piperidinyl is unsubstituted or substituted by at least one substituent independently selected from R6a each R3 is independently selected from hydrogen and C1-10 alkyl each R4 is independently selected from hydrogen, halogen and C1-10 alkyl or R3 and R4 together with the carbon atoms to which they are attached, form a 5-membered ring containing 2 nitrogen heteroatoms and optionally substituted with 1-2 R6b groups each R5 is independently selected from -S(O)rR7 each R6a is independently selected from C1-10 alkyl, -OR8, -S(O)rR7, -(CR9R10)tOR8, -(CR9R10)tS(O)rR8, -(CR9R10)tCO2R8, -(CR9R10)tCONR7R8, -C(O)R7, -C(O)(CR9R10)tOR8, -C(O)(CR9R10)tNR7R8, -CO2R8 and -C(O)NR7R8 each Rb6 is independently selected from C1-10 alkyl each R7 and each R8 are independently selected from hydrogen, C1-10 alkyl and C3-10 cycloalkyl or R7 and R8 together with the atom(s) to which they are attached, form a heterocyclic 5-6-membered ring containing 1 additional heteroatom selected from oxygen and NR11 each R9 and each R10 are independently selected from hydrogen and C1-10 alkyl each R11 is independently selected from hydrogen and C1-10 alkyl each m is independently selected from 0, 1, and 2 each n is 1 each p is independently selected from 1, 2 and 3 each q is independently selected from 0, 1, 2, and 3 each r is 2 each t is ind
