Abstract: The invention provides pyrrolo[3,2-d]pyrimidine derivatives represented by formula (I), and their medically acceptable salts. The compounds of the invention exhibit GSK-3 inhibiting activity and are therefore expected to be useful as therapeutic or prophylactic agents for conditions in which GSK-3 is implicated, such as diabetes, diabetes complications, Alzheimer's disease, neurodegenerative diseases, manic depression, traumatic encephalopathy, alopecia, inflammatory diseases, cancer and immune deficiency.

Abstract: A compound having GSK-3 inhibiting function. A1 and A3 are a single bond, an aliphatic hydrocarbon group; A2 and A4 are a single bond, CO, COO, CONR, O, OCO, NR, NRCO, NRCOO, etc.; G1 is a single bond, an aliphatic hydrocarbon, aromatic hydrocarbon, heterocyclic; G2 is a hydrogen atom, an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, heterocyclic; A5 is a single bond, NR; R2 is H, halogen, an aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, heterocyclic; A6 is a single bond, NR, CO, NRCO, NRCONR, CONR, COO, O, etc.; R3 is H, halogen, nitro, saturated aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, heterocyclic; and when A6 is CR?CR or C?C; R3 may be a trimethylsilyl, formyl, acyl, carboxyl, alkoxylcarbonyl, carbamoyl, alkylcarbamoyl or cyano group; and R is H or an aliphatic hydrocarbon group.