Aziridine

Oxirane

Thiirane

Azetidine

Oxetane

Thietane

Azetidine-2

Pyrrolidine

Pyrroline

Pyrazole

Pyrroles

Imidazoline

Imidazole

Isothiazole

Furan

Isoxazole

Oxazole

Oxazoline

1, 2, 5 -oxadiazole

1, 2, 3 -oxadiazole

1, 2, 4 -oxadiazole

1, 3, 4 -oxadiazole

Tetrazole

Thiophene

Thiazole

Thiazolidine

Piperidine

Piperazine

Morpholine

1, 2, 4 -triazine

1, 3, 5 -triazine

pyridine

2H -pyran

4H -pyran

Pyrazine

Pyridazine

Pyrimidine

4 -piperidinone

Azepane

Oxepane

Thiepane

Benzothiophene

Benzofuran

Indole

Benzimidazole

Benzotriazole

Indazole

Imidazopyridine

Indoline

Purine

Quinoline

Isoquinoline

Quinazoline

1,4 benzodioxan

Carbazole

Acridine