[C:1](O[K])(C)(C)C.[CH3:7][O:8][C:9]1[CH:10]=[N:11][C:12]2[CH:13]=[CH:14][CH:15]=[C:16]([CH:19]=O)[C:17]=2[N:18]=1>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1.CCOCC>[CH3:7][O:8][C:9]1[CH:10]=[N:11][C:12]2[C:17](=[C:16]([CH:19]=[CH2:1])[CH:15]=[CH:14][CH:13]=2)[N:18]=1A suspension of methyltriphenylphosphonium bromide (22.78 g) in THF (200 mL) was treated with tBuOK (7.15 g) and further stirred at rt for 1 h. The mixture was cooled to 0° C. and treated with a solution of 3-methoxy-5-quinoxalinecarboxaldehyde (10.0 g; prepared according to WO 2006/021448) in THF (100 mL). The mixture was further stirred at rt for 3 h, diluted with ether and washed with water and an aq. sat. NH4Cl solution. The org. phase was dried over MgSO4 and concentrated under reduced pressure. The residue was crystallized from ether and the crystals were filtered off. The mother liquor was purified by CC (Hex/EA 1:1), affording a light orange solid (8.70 g; 88% yield).
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