中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
4-氨基-苯并吡喃-2-酮 | 4-aminocoumarin | 53348-92-8 | C9H7NO2 | 161.16 |
A facile protocol for the unprecedented one-pot H2SO4-mediated hydroxymethylation/cyclative N,O-acetalization of 4-aminocoumarins to 1,4-dihydro-2H,5H-chromeno[4,3-d][1,3]oxazin-5-ones, in moderate to good yields, was developed and optimized. The scope and limitations of the transformation, which takes place in water or water/THF mixtures, were also studied. The nitrogen atom of the resulting tricycles was used to tether alkyl, aryl and 1,2,3-triazolylmethyl moieties, employing a two-step click chemistry approach for the latter. The photophysical properties of the heterocycles, as well as of their 1,2,3-triazole derivatives, were also examined. The N-aryl derivatives exhibited high quantum yields of fluorescence (up to Φf = 0.69) and very large Stokes shifts (up to 201 nm).