| 1 | 254-03-5 | 4H-chromene | C9H8O | 132.15922 | | |
| 2 | 254-04-6 | 2H-chromene | C9H8O | 132.15 | | |
| 3 | 254-12-6 | 2H-Pyrano[3,2-c]pyridine (8CI,9CI) | C8H7NO | 133.15 | | |
| 4 | 254-17-1 | 4H-1,3-Benzoxazine | C8H7NO | 133.15 | | |
| 5 | 254-18-2 | Benzoxazine | C8H7NO | 133.15 | | |
| 6 | 254-27-3 | 4H-1,3-benzodioxin | C8H8O2 | 136.15 | | |
| 7 | 254-30-8 | 4H-1,3-Dioxino[4,5-c]pyridine(9CI) | C7H7NO2 | 137.14 | | |
| 8 | 254-35-3 | Phosphinoline | C9H7P | 146.13 | | |
| 9 | 254-36-4 | 4H-1-Benzothiopyran | C9H8S | 148.22 | | |
| 10 | 254-37-5 | 2H-1-Benzothiopyran | C9H8S | 148.22 | | |
| 11 | 254-38-6 | 1-Benzothiopyrylium (8CI,9CI) | C9H7S+ | 147.21 | | |
| 12 | 254-56-8 | 4H-1-Benzoselenin | C9H8Se | 195.12 | | |
| 13 | 254-60-4 | Naphthyridine | C8H6N2 | 130.15 | 99.8-99.9°C | |
| 14 | 254-61-5 | Pyrido[2,3-d]pyrimidine (7CI,8CI,9CI) | C7H5N3 | 131.13 | | |
| 15 | 254-62-6 | Pyrimido[4,5-c]pyridazine (7CI,8CI,9CI) | C6H4N4 | 132.12 | | |
| 16 | 254-64-8 | Pyrimido[4,5-d]pyrimidine (8CI,9CI) | C6H4N4 | 132.12 | | |
| 17 | 254-69-3 | 7H-Pyrano[2,3-d]pyrimidine (8CI,9CI) | C7H6N2O | 134.14 | | |
| 18 | 254-72-8 | 5H-Thiopyrano[2,3-d]pyrimidine (8CI,9CI) | C7H6N2S | 150.2 | | |
| 19 | 254-79-5 | Naphthyridine | C8H6N2 | 130.15 | 69-75 °C | |
| 20 | 254-80-8 | Pyrido[3,2-d]pyrimidine (7CI,8CI,9CI) | C7H5N3 | 131.13 | | |
| 21 | 254-82-0 | Pyrimido[5,4-d]pyrimidine (7CI,8CI,9CI) | C6H4N4 | 132.12 | | |
| 22 | 254-83-1 | Pyrimido[5,4-d]-1,2,3-triazine (9CI) | C5H3N5 | 133.11 | | |
| 23 | 254-86-4 | Pyrido[3,4-b]pyrazine (6CI,7CI,8CI,9CI) | C7H5N3 | 131.137 | | |
| 24 | 254-87-5 | 1,2,4-benzotriazene | C7H5N3 | 131.13 | 75.8°C | |
| 25 | 254-95-5 | Pyrazino[2,3-d]pyridazine | C6H4N4 | 132.12 | | |
| 26 | 254-96-6 | Pyrazino[2,3-c]pyridazine | C6H4N4 | 132.12 | | |
| 27 | 254-97-7 | Pyrido[2,3-e][1,2,4]triazine | C6H4N4 | 132.12 | | |
| 28 | 254-99-9 | Pyrimido[5,4-e]-1,2,4-triazine (9CI) | C5H3N5 | 133.11 | | |