[Br-].[CH2:2]([O:4][C:5]([CH2:7][N+:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[CH2:14][C:15]([O:17][CH2:18][CH3:19])=[O:16])=O)[CH3:3].Br[CH2:21]CCBr.[OH-].[K+]>C(O)C.O>[O:4]1[C:5]2[C:14]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[C:9]3[N:8]([C:7]=2[CH2:21][CH2:3][CH2:2]1)[CH:13]=[CH:12][CH:11]=[CH:10]3A solution of 1,2-di-[(ethoxycarbonyl)methyl]pyridinium bromide (1.5 g, 0.0045 mole) and 1,3-dibromopropane (0.45 ml, 0.0045 mole) in ethanol (10 ml) was added over 5 minutes to a stirred solution of potassium hydroxide (0.75 g, 0.0134 mole) in ethanol (15 ml) at 5° C. The mixture was then allowed to warm upto room temperature and stir for 20 h. The reaction mixture was diluted with water (150 ml) and extracted with ethyl acetate (2×100 ml). The combined extracts were dried (Na2SO4) and concentrated in vacuo to leave a brown oil. This was chromatographed on silica gel eluting with ether to afford the title compound as a yellow oil.
Wird geladen…
