[NH:1]1[CH2:6][CH2:5][O:4][CH2:3][CH2:2]1.[CH3:7][N:8]1[CH:12]=[CH:11][CH:10]=[C:9]1[CH:13]=[O:14].[CH2:15]=O>C(O)(=O)C.O>[CH3:7][N:8]1[CH:12]=[C:11]([CH2:15][N:1]2[CH2:6][CH2:5][O:4][CH2:3][CH2:2]2)[CH:10]=[C:9]1[CH:13]=[O:14].[CH3:7][N:8]1[C:12]([CH2:15][N:1]2[CH2:6][CH2:5][O:4][CH2:3][CH2:2]2)=[CH:11][CH:10]=[C:9]1[CH:13]=[O:14]To a solution of morpholine (130 mmoles) in acetic acid (60 ml) at 0° C. there are added 1-methyl-1H-pyrrole-2-carbaldehyde (110 mmoles) and formaldehyde (110 mmoles) 37% in water. The reaction mixture is stirred for 16 hours at 50° C. After evaporation to dryness, about 100 ml of 25% aqueous sodium hydroxide solution are added. After extraction with DCM, the organic phase is washed with water and with saturated aqueous NaCl solution, dried over sodium sulphate, filtered and evaporated to dryness. The residue is purified by flash chromatography on silica gel (SiO2; gradient AcOEt/MeOH) to yield the title products 1-methyl-4-morpholin-4-ylmethyl-1H-pyrrole-2-carbaldehyde and 1-methyl-5-morpholin-4-ylmethyl-1H-pyrrole-2-carbaldehyde in a ratio of 1/5.
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