| 253-66-7 | 1,2-二氮萘 |
| 253-69-0 | 1,7-萘啶 |
| 253-72-5 | 1,6-二氮萘 |
| 253-73-6 | 3,4,10-triazabicyclo[4.4.0]deca-1,3,5,7,9-pentaene |
| 253-82-7 | 喹唑啉 |
| 253-86-1 | Pyrido[3,4-d]pyrimidine (7CI,8CI,9CI) |
| 253-87-2 | Pyrido[4,3-d]pyrimidine (7CI,8CI,9CI) |
| 253-88-3 | Pyrimido[4,5-d]pyridazine (7CI,8CI,9CI) |
| 253-89-4 | 5H-Thiopyrano[4,3-d]pyrimidine (8CI,9CI) |
| 254-04-6 | 254-04-6 |
| 254-18-2 | Benzoxazine |
| 254-27-3 | 4H-1,3-benzodioxin |
| 254-30-8 | 4H-1,3-Dioxino[4,5-c]pyridine(9CI) |
| 254-60-4 | 1,8-萘啶 |
| 254-61-5 | PYRIDO[2,3-D]PYRIMIDINE |
| 254-62-6 | Pyrimido[4,5-c]pyridazine (7CI,8CI,9CI) |
| 254-64-8 | Pyrimido[4,5-d]pyrimidine (8CI,9CI) |
| 254-69-3 | 7H-Pyrano[2,3-d]pyrimidine (8CI,9CI) |
| 254-72-8 | 5H-Thiopyrano[2,3-d]pyrimidine (8CI,9CI) |
| 254-79-5 | 1,5-萘啶 |
| 254-80-8 | Pyrido[3,2-d]pyrimidine (7CI,8CI,9CI) |
| 254-82-0 | Pyrimido[5,4-d]pyrimidine (7CI,8CI,9CI) |
| 254-83-1 | Pyrimido[5,4-d]-1,2,3-triazine (9CI) |
| 254-86-4 | 吡啶并[3,4-B]吡嗪 |
| 254-99-9 | Pyrimido[5,4-e]-1,2,4-triazine (9CI) |
| 255-01-6 | Pyrimido[4,5-e]-1,2,4-triazine (9CI) |
| 255-12-9 | 5H-Pyrimido[4,5-b][1,4]oxazine (8CI,9CI) |
| 255-13-0 | 7H-Pyrimido[4,5-b][1,4]oxazine (8CI,9CI) |
| 255-37-8 | 1,4-Benzodioxin |
| 255-55-0 | 1,4-二THIINO[2,3-B]-1,4-二THIIN |
| 255-85-6 | 4H,6H-Pyrido1,2-c1,3,5oxadiazine |
| 256-80-4 | 10H-Dibenzo[a,d]cycloheptene |
| 256-81-5 | 二苯并环庚烯 |
| 256-86-0 | 11H-Dibenz[b,e]azepine |
| 256-90-6 | dibenzo(c,f)(1,2)diazepine |
| 256-91-7 | 11H-Dibenzo[c,f][1,2]diazepine |
| 256-96-2 | 亚氨基芪 |
| 257-05-6 | Dibenz[b,f]oxepin |
| 257-07-8 | 二苯并[B,F][1,4]噁唑频 |
| 257-13-6 | Dibenzo[b,f]thiepin |
| 257-24-9 | 【草(之上)+黑】 |
| 257-25-0 | 三乙氧基镓 |
| 257-89-6 | Benz[b]acridine |
| 257-97-6 | N,N'-(2,3-Naphthalenediyl)-1,2-benzoquinone diimine |
| 258-31-1 | 并六苯 |
| 258-47-9 | 2,3:6,7-Bis[1,3]butadienobiphenylene |
| 258-76-4 | Dibenzo[b,i]phenazine |
| 258-78-6 | 13H-Dibenzo[b,i]phenothiazine |
| 258-91-3 | Benzo[b]naphtho[2,3-f][1,4]diazocine |
| 259-77-8 | Pentacyclo[6,4,0,0] 2,7 [0]4,11,[0]5,10 dodecane |
| 259-79-0 | 联苯烯 |
| 259-79-0 | Biphenylene |
| 259-84-7 | 1,8-DIAZABIPHENYLENE |
| 260-47-9 | 4H-Naphtho2,3-d-1,3,2-dioxathiin |
| 260-50-4 | 苯并[G]喹喔啉 |
| 260-62-8 | 4,5-Didehydro-4H-benzo[b]quinolizine-5-ium |
| 260-75-3 | 嘧啶并[4,5- G]喹唑啉 |
| 260-94-6 | 吖啶 |
| 260-94-6 | 2,3-Benzoquinoline |
| 261-05-2 | benzo(b)1,5-naphthyridine |
| 261-23-4 | Xanthylium |
| 261-27-8 | 9-氧杂-1-氮杂-蒽 |
| 261-31-4 | 阿奇霉素杂质B |
| 261-42-7 | 吨碲 |
| 261-65-4 | 1,3,9,10-Tetraazaanthracene |
| 261-96-1 | 氮杂苯酚噻嗪 |
| 261-99-4 | 1,2-DIAZAPHENOTHIAZINE |
| 262-05-5 | 10H-吩硒嗪 |
| 262-09-9 | BISCHLOROACETYLETHYLINEDIAMINE |
| 262-12-4 | 二苯并-对-二恶英 |
| 262-16-8 | 1,4 - 二并(2,3,B,5,6,B')联吡啶 |
| 262-20-4 | 吩恶噻 |
| 262-22-6 | 9-Oxa-10-selenaanthracene |
| 262-50-0 | 3,4-Methylenedioxy benzylamine |
| 262-76-0 | Corrinoid |
| 262-89-3 | PhenylboronicAcidAnhydride(2,4,6-TriphenylBoroxine) |
| 262-89-5 | 二苯并[A,E]环辛烯 |
| 262-98-6 | Dibenzo[c,g][1,2]diazocine |
| 262-99-7 | phenhomazine |
| 264-09-5 | 9H-苯并[7]环轮烯 |
| 264-17-5 | 2H-2-Benzazepine |
| 264-33-5 | Oxepino4,5-cpyridine |
| 264-95-9 | 5H-Cycloheptapyrimidine (8CI,9CI) |
| 264-96-0 | 9H-Cycloheptapyrimidine (8CI,9CI) |
| 264-98-2 | 6H-Pyrimido[4,5-e][1,4]diazepine (8CI,9CI) |
| 265-17-8 | 2H-Pyrimido[4,5-f]-1,2,4,5-tetrazepine (9CI) |
| 267-26-5 | 5H-Indeno[5,6-d]isoxazole(9CI) |
| 267-36-7 | Benzo[1,2-b:4,5-c]difuran (8CI,9CI) |
| 267-37-8 | Furo[3,4-f]-1,2-benzisoxazole (9CI) |
| 267-39-0 | 1H-Furo[3,4-f]benzimidazole(8CI,9CI) |
| 267-41-4 | Furo[3,4-f]benzothiazole (8CI,9CI) |
| 267-47-0 | 5H-Furo[2,3-f]indole |
| 267-48-1 | 5,6-亚甲基二氧基吲哚 |
| 267-53-8 | 4H,8H-Benzo[1,2-c:5,4-c]diisoxazole(8CI,9CI) |
| 267-54-9 | [1,3]Dioxolo[4,5-f]-2,1-benzisoxazole(8CI,9CI) |
| 267-56-1 | Benzo[1,2-b:5,4-b]difuran (8CI,9CI) |
| 267-57-2 | Furo[3,2-f]-1,2-benzisoxazole (8CI,9CI) |
| 267-58-3 | |
| 267-60-7 | Benzo[1,2-d:5,4-d]diisoxazole (8CI,9CI) |
| 267-61-8 | 苯并[1,2-B:5,4-B']二噻吩 |