中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | 2-(3-chlorophenyl)-1,5-dimethyl-1,2-dihydro-3H-pyrazol-3-one | 87634-62-6 | C11H11ClN2O | 222.674 |
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.