Ethyl orthoformate → HCID 178486900, Verbindung
Reaktionsgleichung
[Br:1][C:2]1[CH:3]=[C:4]([NH2:11])[C:5]([NH2:10])=[CH:6][C:7]=1[O:8][CH3:9].[CH:12](OCC)(OCC)OCC>C(O)=O>[Br:1][C:2]1[C:7]([O:8][CH3:9])=[CH:6][C:5]2[NH:10][CH:12]=[N:11][C:4]=2[CH:3]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
To a stirred mixture of 4-bromo-5-methoxybenzene-1,2-diamine (3.8 g, 18 mmol) from Step 1 of this Example and triethyl orthoformate (50 mL) was added formic acid (1 mL). The mixture was heated at reflux for 3 h, then concentrated under reduced pressure. The residue was partitioned between EtOAc (200 mL) and a 1 N aq Na2CO3 (100 mL). The EtOAc layer was separated, washed with brine (100 mL), dried over Na2SO4, filtered, and concentrated under reduced pressure to afford 5-bromo-6-methoxy-1H-benzo[d]imidazole (4.0 g) as a brown oil. The material was used in the next step without further purification. LCMS (ESI) m/z 228 and 230 (M+H)+.