Provided are a compound of a formula (I) and its pharmaceutically-acceptablesalt, which have a glucokinase-activating effect and are therefore useful fortreatment of diabetesand obesity.(see formula I)[In the formula, R1 and R2 each independently represent a lower alkyl group；X1 represent agroup of a formula (II-1):(see formula II-1)(wherein R11 and R12 each independently represent a hydrogen atom or a loweralkyl group, ortaken together with the nitrogen atom to which they are attached, R11 and R12may form a 4- to7-membered nitrogen-containing aliphatic ring (one carbon atom constitutingthe 4- to 7-membered nitrogen-containing aliphatic ring may be replaced by an oxygenatom), or takentogether with a carbon atom in (CH2)m, R11 and R12 may form a 4- to 7-memberednitrogen-containing aliphatic ring； m indicates an integer of from 1 to 3).]
