Methanol → Methyl 3-amino-4,5-dimethyl-1H-pyrrole-2-carboxylate

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Reaction Steps

2-Amino-malonic acid dimethyl ester hydrochloride (8.51 g, 46.3 mmol) and sodium acetate (3.8 g, 46.3 mmol) is added to a mixture of 2-methyl-3-oxo-butyronitrile (3.0 g, 30.9 mmol), methanol (60 ml) and water (12 ml) and stirred at RT for 17 h. The mixture is concentrated in vacuo to 20 ml and extracted with EtOAc. The combined organic layers are dried over MgSO4 and concentrated in vacuo. Methanol (100 ml) and sodium methoxide (5.4 mol/l in MeOH, 6 ml, 32.4 mmol) is added and the mixture stirred at 65° C. for 3 hours. Water is added at RT and the mixture extracted with EtOAc. The combined organic layers are dried over MgSO4 and concentrated in vacuo. The product is purified by RP HPLC. Yield: 2.2 g (42%). HPLC-MS: M+H=169; tR=0.52 min (METHOD—1).

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