[CH2:1]([NH:3][CH2:4][CH3:5])[CH3:2].C[Al](C)C.C(O[C:13]([C:15]1[CH:19]=[CH:18][NH:17][C:16]=1[CH3:20])=[O:14])C.Cl>C1(C)C=CC=CC=1.CCCCCC>[CH2:1]([N:3]([CH2:4][CH3:5])[C:13]([C:15]1[CH:19]=[CH:18][NH:17][C:16]=1[CH3:20])=[O:14])[CH3:2]To a solution of 1.6 ml of diethylamine in 30 ml of toluene was added 7.5 ml of 2M trimethylaluminum in hexane, and the mixture stirred for 20 minutes. To this mixture was added 1.53 g of 2-methylpyrrole-3-carboxylic acid ethyl ester, and the reaction mixture refluxed overnight. The mixture was cooled, acidified with aqueous 2N hydrochloric acid and extracted twice with ethyl acetate and three times with methylene chloride. Solvent was removed from the combined extracts under reduced pressure, and the residue was flash chromatographed on silica gel, eluting with 75% ethyl acetate/hexane, giving 1.5 g of 2-methylpyrrole-3-carboxylic acid diethylamide, m.p. 120°-121° C., the compound of formula (b).
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