Fragments C—C, C—C, N, and C
Fragments C—C—C, N—C, and C
Fragment C—C—N—C—C—C
Fragments C—N—C and C—C—C
Fragments C—N—C, C—C, and C
Fragments N–C–N and C–C–C
Fragments N–C–C–C–N and C
Fragments C—C—C—N and N—C
Fragments C–N–C, C–C, and N