[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:9]([C:11]([OH:13])=O)[CH2:8][CH:7]([OH:14])[C:6]=2[CH:15]=1.ClC1C=CC2OC(C(O)=O)CC(=O)C=2C=1.[BH4-].[Na+].[CH2:33]([NH2:36])[CH:34]=[CH2:35]>C(O)C>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:9]([C:11]([NH:36][CH2:33][CH:34]=[CH2:35])=[O:13])[CH:8]=[C:7]([OH:14])[C:6]=2[CH:15]=1A solution of 512 mg of the ethyl ester of 6-chloro-3,4-dihydro-4-hydroxy-2H-1-benzopyran-2-carboxylic acid, (prepared by treating the ethyl ester of 6-chloro-3,4-dihydro-4-oxo-2H-1-benzopyran-2-carboxylic acid (Witiak et al., supra) with sodium borohydride), 570 mg of 2-propenamine and 20 ml of ethanol was stirred at room temperature for 72 hours, then stirred for 3 hours while heated by a steam bath. The solvent was stripped off and the residue was crystallized from methylene chloride/hexane to give 7, as white crystals, mp: 129°-130.5° C.
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