[CH2:1]([O:8][C:9]1[CH:18]=[C:17]2[C:12]([C:13]([OH:20])=[CH:14][C:15](=[O:19])[O:16]2)=[CH:11][CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C.C1(C)C=CC(S([N:37]=[N+:38]=[N-])(=O)=O)=CC=1>C1COCC1>[N+:37](=[C:14]1[C:13](=[O:20])[C:12]2[C:17](=[CH:18][C:9]([O:8][CH2:1][C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=3)=[CH:10][CH:11]=2)[O:16][C:15]1=[O:19])=[N-:38]A solution of 7-benzyloxy -4-hydroxy coumarin (2.5 g, 9.3 mmol; prepared in accordance with Example 5) in anhydrous THF (40 mL) was mixed with triethylamine (0.9 g, 9 mmol) taken in a 100 mL 3-neck round-bottom flask under an atmosphere of N2. A solution of p-toluenesulfonyl azide (2.8 g, 14 mmol) in dry THF (20 mL) was added dropwise through an addition funnel. The mixture was stirred at room temperature for 3 hrs. The color of the solution turned orange. The solvent was rotary evaporated and the product was taken in CH2Cl2 and washed with water (3 times). Petroleum ether (twice the volume) was added to the solution and the solid precipitate was filtered with a flit and dried at 45° C. The product was recrystallized using CH2Cl2 ; yield 90%. The product was characterized by NMR: 13C NMR (100 MHz, CD2 Cl2): 173.3, 165.4, 158.7, 156.0, 136.0, 129.1, 128.8, 128.0, 127.6, 113.9, 113.0, 103.0, 75.7, 71.2; DSC--m. pt. 191° C. followed by decomposition; IR (KBr): 2182, 2154, 1717, 1647, 1605 cm-1 ; MS(APCI): (M+H), 295 (base peak).
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