C([Mg]Br)(C)C.CN(C)[CH:8]=[O:9].O.[Br:12][C:13]1[C:14]([CH3:20])=[CH:15][C:16](I)=[N:17][CH:18]=1>O1CCCC1>[Br:12][C:13]1[C:14]([CH3:20])=[CH:15][C:16]([CH:8]=[O:9])=[N:17][CH:18]=1In an oven-dried flask the compound obtained in Step A (4.67 g) was dissolved in tetrahydrofuran (22 ml). The solution was cooled to −15° C., then isopropyl magnesium bromide (17.2 ml, 15% solution in THF) was added dropwise at a rate to keep the internal temperature between −15° C. to −10° C. The reaction was stirred at this temperature for 1 hour, then anhydrous dimethylformamide (1.8 ml) was added at a rate to keep the internal temperature below 0° C. The reaction was stirred at this temperature for 1 hour, then poured into water and extracted with diethyl ether. The organic layer was dried over sodium sulfate and concentrated in vacuo. The crude title aldehyde product (2.4 g, brown solid) was used as such in the next step.
Wird geladen…
