Synthesis of 6-quinoxalinyldihydropyrazolo[1,5-<i>a</i>]pyrimidin-7-ones by a ring transformation. Tautomeric structure of dihydropyrazolo[1,5-<i>a</i>]pyrimidin-7-ones in a solution
作者:Yoshihisa Kurasawa、Ho Sik Kim、Atsushi Takada、Yoshihisa Okamoto
DOI:10.1002/jhet.5570270761
日期:1990.11
The reaction of 3-(N,N-dimethylcarbamoyl)furo[2,3-b]quinoxaline hydrochloride 1 with the 5-aminopyrazoles 6a-e gave 6-quinoxalinyldihydropyrazolo[1,5-a]pyrimidin-7-ones 7a-e, respectively. Compounds 7a-e were found to predominate as the 4,7-dihydro-7-oxo form in a solution based on the NOE data.
3-(N,N-二甲基氨基甲酰基)呋喃[2,3- b ]喹喔啉盐酸盐1与5-氨基吡唑6a-e的反应得到6-喹喔啉基二氢吡唑并[1,5 - a ]嘧啶-7-酮7a-e, 分别。基于NOE数据,发现化合物7a-e在溶液中以4,7-二氢-7-氧代形式占主导。