中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
1,2-二氢-5-乙基-1-甲基-2-苯基-3H-吡唑-3-酮 | 1,2-dihydro-5-ethyl-1-methyl-2-phenyl-3H-pyrazol-3-one | 109249-29-8 | C12H14N2O | 202.256 |
Heating of squaric acid (1) with the 1-aryl-3-methyl-5-oxo-2,5-dihydro-1H-pyrazoles 3a - j and the 1,3-disubstituted pyrazolinones 7a - d in the molar ratio of 1:2 in a mixture of n-BuOH/toluene afforded the bis(pyrazolyl)-squaraines 4a - j and 8a - d, respectively. Reaction of an excess of 1 with the pyrazolinone 3j yielded 4j and the 3-hydroxy-4-pyrazolyl-cyclobutene-1,2-dione 6 as a byproduct. In contrast to disubstituted pyrazolinones, the trisubstituted pyrazolinones 9a - e reacted with squaric acid (1) to give the hydroxy-oxopyrazolyl-cyclobutenediones 10a - e.