Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo, Via Archirafi, 32, 90123-Palermo, Italy.
Molecules. 2013 Oct 22;18(10):13096-110. doi: 10.3390/molecules181013096.
The compound 2-((1,3-dimethyl-1H-pyrazol-5-yl)(methyl)carbamoyl)benzene-diazonium hydrogen sulfate (10) was reacted with copper sulfate and sodium chloride, in the presence of ascorbic acid as reducing agent, to afford a mixture of the chlorinated epimers 4'-chloro-2,2',5'-trimethyl-2',4'-dihydrospiro[isoindoline-1,3'-pyrazol]-3-one (18) and (19), the epimers 4'-hydroxy-2,2',5'-trimethyl-2',4'-dihydrospiro[isoindoline-1,3'-pyrazol]-3-one (20) and (21), and N-(1,3-dimethyl-1H-pyrazol-5-yl)benzamide (22). Under the foregoing conditions, diazonium salt 10 affords neither the 2-chloro-N-(1,3-dimethyl-1H-pyrazol-5-yl)-N-methylbenzamide (23) nor the tricyclic derivative 24, the classical products of the Sandmeyer and Pschorr reactions, respectively. Finally, by heating 20 at 210 °C the compound 1,3-dimethylisochromeno[4,3-c]pyrazol-5(1H)-one (24) was obtained. The transformation under the above conditions of 2-((4-chloro-3-methyl-1-phenyl- 1H-pyrazol-5-yl)(methyl)carbamoyl)benzendiazonium hydrogen sulphate (11) afforded 4',4'-dichloro-2,5'-dimethyl-2'-phenyl-2',4'-dihydrospiro[isoindoline-1,3'-pyrazol]-3-one (29) as the sole reaction product.
化合物 2-((1,3-二甲基-1H-吡唑-5-基)(甲基)氨基甲酰基)苯重氮氢硫酸盐（10）与硫酸铜和氯化钠反应，在抗坏血酸作为还原剂的存在下，得到氯化差向异构体 4'-氯-2,2',5'-三甲基-2',4'-二氢螺[异吲哚啉-1,3'-吡唑]-3-酮（18）和（19）、差向异构体 4'-羟基-2,2',5'-三甲基-2',4'-二氢螺[异吲哚啉-1,3'-吡唑]-3-酮（20）和（21）以及 N-(1,3-二甲基-1H-吡唑-5-基)苯甲酰胺（22）的混合物。在上述条件下，重氮盐 10 既不生成 2-氯-N-(1,3-二甲基-1H-吡唑-5-基)-N-甲基苯甲酰胺（23），也不生成分别为 Sandmeyer 和 Pschorr 反应的经典产物三环衍生物 24。最后，通过将 20 在 210°C 下加热，得到 1,3-二甲基异色满[4,3-c]吡唑-5(1H)-酮（24）。在上述条件下，将 2-((4-氯-3-甲基-1-苯基-1H-吡唑-5-基)(甲基)氨基甲酰基)苯重氮氢硫酸盐（11）转化为唯一的反应产物 4',4'-二氯-2,5'-二甲基-2'-苯基-2',4'-二氢螺[异吲哚啉-1,3'-吡唑]-3-酮（29）。
