COC([O:5][C:6]1[C:7]([CH3:18])=[N:8][CH:9]=[C:10]([CH2:12][O:13][C:14]([O:16][CH3:17])=[O:15])[CH:11]=1)=O.Br.C(=O)(O)[O-].[Na+]>C(O)C>[CH3:17][O:16][C:14]([O:13][CH2:12][C:10]1[CH:11]=[C:6]([OH:5])[C:7]([CH3:18])=[N:8][CH:9]=1)=[O:15]A solution of 1 g. of 3-methoxycarbonyloxy-5-methoxycarbonyloxymethyl-2-methylpyridine in an aqueous ethanol (10 ml. of ethanol and 5 ml. of water) was adjusted to pH 1-1.5 with 10% hydrobromic acid. The mixture was heated at 90°C for 30 minutes, then cooled and neutralized with sodium bicarbonate and extracted with ethyl acetate. The extract was dried over anhydrous sodium sulfate and concentrated into a small volume and the addition of n-hexane gave 0.45 g. of the desired product as colorless crystals melting at 187°-189°C, which showed no depression of melting point on admixture with the authentic sample and the IR spectrum coincided with that of the standard completely.
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