The application of the Sandmeyer reaction to 2-amino-3-nitrocarbazole (1) gave 2-cyano-3-nitrocarbazole (5), which could be reduced to 3-amino-2 cyanocarbazole (6), 3-amino-2-carbamoylcarbazole (8) or 3-amino-2-methylcarbazole (9) according to the reaction conditions used. Intramolecular cyclization of the carbazoles (6), (7) and (8) afforded 3, 4-dihydro-4-oxo-6H-pyrimidino [5, 4-b] carbazoles (11), (12) and (13). 4-Amino-6H-pyrimidino [5, 4-b] carbazole (14) was obtained by cyclization of 3-amino-2-cyano-carbazole (6) with formamide. Treatment of 3-amino-2-carbamoylcarbazole (8) with carbonyl chloride gave 1, 2, 3, 4-tetrahydro-2, 4-dioxo-6H-pyrimidino-[5, 4-b] carbazole (15). The proton nuclear magnetic resonance spectra of the products were studied.
将Sandmeyer反应应用于2-
氨基-
3-硝基
咔唑(1)得到2-
氰基-
3-硝基
咔唑(5),根据反应条件不同,可进一步还原为3-
氨基-2-
氰基
咔唑(6)、3-
氨基-2-
氨基甲酰基
咔唑(8)或3-
氨基-
2-甲基咔唑(9)。
咔唑(6)、(7)和(8)的分子内环化反应得到3,4-二氢-4-氧代-6H-
嘧啶并[5,4-b]
咔唑(11)、(12)和(13)。4-
氨基-6H-
嘧啶并[5,4-b]
咔唑(14)是通过3-
氨基-2-
氰基
咔唑(6)与甲酰胺的环化反应得到的。3-
氨基-2-
氨基甲酰基
咔唑(8)与羰基
氯反应得到1,2,3,4-四氢-2,4-二氧代-6H-
嘧啶并[5,4-b]
咔唑(15)。研究了产物的质子核磁共振光谱。