| 1 | 290-03-9 | 4H-1,3-Oxazine | 4H-1,3-Oxazine | | | |
| 2 | 290-04-0 | 2H-1,3-Oxazine | 2H-1,3-Oxazine | C4H5NO | | |
| 3 | 290-05-1 | | 2H-1,3,2-Oxazaphosphorine | C3H4NOP | | |
| 4 | 290-09-5 | 1,2,6-Oxathiazine | 1,2,6-Oxathiazine | | | |
| 5 | 290-13-1 | | 4H-1,3-Dioxin | C4H6O2 | | |
| 6 | 290-16-4 | 4H-1,3,2-Dioxathiin | 4H-1,3,2-Dioxathiin | | | |
| 7 | 290-19-7 | | 1,3-Dioxa-2-silacyclohexane | C3H8O2Si | | |
| 8 | 290-21-1 | 4H-1,3-Oxathiin | 4H-1,3-Oxathiin | | | |
| 9 | 290-27-7 | 3H-1,2,6-Oxadithiin | 3H-1,2,6-Oxadithiin | | | |
| 10 | 290-36-8 | | Mercury, (oxodi-2,1-ethenediyl)- (9CI) | C4H4HgO | | |
| 11 | 290-37-9 | 吡嗪 | pyrazine | C4H4N2 | 吡嗪;杂环砌块;通用试剂;日化原料;化工原料;精细化学品;食品添加剂;医药中间体;有机化工原料;对照品,标准品 | 医药中间体;香精中间体;香料中间体 |
| 12 | 290-38-0 | 1,2,5-三嗪 | 1,2,4-Triazine | C3H3N3 | | |
| 13 | 290-42-6 | 1,2,3,4-Tetrazine | 1,2,3,4-Tetrazine | C2H2N4 | | |
| 14 | 290-44-8 | 1,2,4,3-Triazaphosphorine | 1,2,4,3-Triazaphosphorine | C2H2N3P | | |
| 15 | 290-47-1 | 4H-1,4-Oxazine | 4H-1,4-Oxazine | | | |
| 16 | 290-49-3 | 2H-1,2,4-Oxadiazine | 2H-1,2,4-Oxadiazine | C3H4N2O | | |
| 17 | 290-52-8 | 2H-1,3,4-Oxadiazine | 2H-1,3,4-Oxadiazine | | | |
| 18 | 290-57-3 | 4H-1,4-Thiazine | 4H-1,4-Thiazine | | | |
| 19 | 290-58-4 | 1,4-Thiazin-1-ium | 1,4-Thiazin-1-ium | C4H4NS | | |
| 20 | 290-61-9 | 1,2,5-Oxathiazine | 1,2,5-Oxathiazine | C3H3NOS | | |
| 21 | 290-64-2 | 4H-1,3,4-Thiadiazine | 4H-1,3,4-Thiadiazine | C3H4N2S | | |
| 22 | 290-67-5 | 1,4-dioxin | 1,4-dioxin | C4H4O2 | | |
| 23 | 290-72-2 | 1,4-Oxathiin | 1,4-Oxathiin | | | |
| 24 | 290-73-3 | 1,2,4-Oxadithiin | 1,2,4-Oxadithiin | | | |
| 25 | 290-76-6 | 1,4-oxaselenin | 1,4-oxaselenin | C4H4OSe | | |
| 26 | 290-78-8 | | 1,4-Diphosphorin | C4H4P2 | | |
| 27 | 290-79-9 | 1,4-Dithiin | 1,4-Dithiin | C4H4S2 | | |
| 28 | 290-81-3 | 1,2,3,4-TETRATHIANE | 1,2,3,4-TETRATHIANE | C2H4S4 | | |
| 29 | 290-82-4 | | 1,4-Thiaselenin | C4H4SSe | | |
| 30 | 290-83-5 | | 1,4-Diselenin | C4H4Se2 | | |
| 31 | 290-87-9 | 1,3,5-三嗪 | S-triazine (1,3,5) | C12H17N | | |
| 32 | 290-88-0 | 2H-1,3,5-Oxadiazine | 2H-1,3,5-Oxadiazine | | | |
| 33 | 290-93-7 | | 2H-1,2,4,6-Thiatriazine | C2H3N3S | | |
| 34 | 290-96-0 | 均四【口+井】 | s-tetrazine | C2H2N4 | | |
| 35 | 290-97-1 | Pentazine | Pentazine | CHN5 | | |