C[O:2][C:3](=[O:9])[CH2:4][C:5](OC)=O.[Na].ClC1[N:19]=[C:18]([Cl:20])[CH:17]=[CH:16][C:13]=1[C:14]#[N:15].Cl>O.O1CCOCC1>[Cl:20][C:18]1[N:19]=[C:5]([CH2:4][C:3]([OH:2])=[O:9])[C:13]([C:14]#[N:15])=[CH:16][CH:17]=1A mixture of malonic acid dimethyl ester, sodium salt (8.067 g, 52.4 mmol), as prepared in the previous step, 2,6-dichloro-nicotinonitrile (4.53 g, 26.2 mmol), as prepared in Example 6b, and dioxane (40 mL) was stirred at 80° C. for 1 h. The resulting easily stirred reddish-brown opaque thin slurry was allowed to cool to rt, 6 M HCl (aq) (80 mL) was added, and the mixture was vigorously stirred at 65-70° C. for 5 h open to air. The resulting clear dark amber solution containing a small amount of dark material was allowed to cool to rt, diluted with water (80 mL), and extracted with DCM (3×100 mL). The organic layers were combined, dried (2×Na2SO4), and concentrated under reduced pressure at 60° C. to provide the crude title compound as a dark brown oil (6.2 g, quantitative yield). A NMR spectrum of the reaction following malonate addition indicated a ˜1:2 mixture of desired/undesired regioisomers.
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