CON(C)[C:4]([C:6]1[CH:10]=[C:9]([CH2:11][CH3:12])[N:8]([CH2:13][CH3:14])[N:7]=1)=[O:5].[CH3:16][Mg]Br.C(O)C.Cl>O1CCCC1.CCOCC.CCOC(C)=O.O>[C:4]([C:6]1[CH:10]=[C:9]([CH2:11][CH3:12])[N:8]([CH2:13][CH3:14])[N:7]=1)(=[O:5])[CH3:16]
N-Methoxy-N-methyl-1,5-diethylpyrazole-3-carboxamide (10.1 g) in dry tetrahydrofuran (180 ml) was cooled in an ice-bath and treated with a 3.0M solution of methylmagnesium bromide in ether (20.68 ml) added dropwise over 10 minutes. After stirring for 1 hour the mixture was treated with a mixture of ethanol (5 ml) and 5M aqueous HCl (1 ml). The mixture was then diluted with EtOAc and water. The organic phase was separated and the aqueous phase extracted twice with EtOAc. The combined organic extracts were dried over MgSO4 and evaporated in vacuo to leave an oil which was chromatographed on silica gel, loading in dichloromethane, and eluting with ethyl acetate/hexane mixtures to give, after evaporation of the requisite fractions, the product as an oil (8.08 g). δ(CDCl3) 1.29 (3H, t, J 7 Hz), 1.45 (3H, t, J 7 Hz), 2.55 (3H, s), 2.64 (2H, q, J 7 Hz), 4.14 (2H, q, J 7 Hz,), 6.55 (1H,s) ppm.
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