[CH2:1]([O:4][CH2:5][CH:6]=[CH2:7])[CH:2]=[CH2:3].[CH3:8][C:9]1[C:15]2C=CC(O)=[CH:19][C:14]=2[O:13][C:11](=[O:12])[CH:10]=1.[CH3:21][SiH:22]([CH3:24])[Cl:23].C1(C)C=CC=CC=1>O1CCCC1>[Cl:23][Si:22]([CH3:24])([CH3:21])[CH2:3][CH2:2][CH2:1][O:4][C:5]1[CH:19]=[C:14]2[C:15]([C:9]([CH3:8])=[CH:10][C:11](=[O:12])[O:13]2)=[CH:7][CH:6]=1A glass pressure bottle was charged with 21.6 g of the allyl ether of 4-methylumbelliferone, 11 mls of dimethylmonochlorosilane, 25 mls of toluene and 0.1 cc of a 0.1M H2PtCl6 solution in tetrahydrofuran. The mixture was heated to 140 degrees C. at 40 psi for 15 hours. Toluene was removed by rotary evaporation. The title product was recovered in a yield of 27 g at greater than 70% purity as determined by proton NMR. A broad UV absorption spectrum was observed with maxima at 319.5, 281, 248 and 223 nanometers (nm). The extinction coefficient at 319.5 was greater than 20,000. Fluorescence spectra obtained after excitation at 384 nm gave maxima at 390 (v.s.), 421, 521, and 585 nm.
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