Synthesis of pyrazolo[1,5-a]indoles via copper(I)-catalyzed intramolecular amination

Tetrahedron Letters

Volumn 48, Issue 36, 2007, Pages 6262-6266

  Zhu, Yong Ming ^a   Qin, Lie Na ^a   Liu, Rui ^a   Ji, Shun Jun ^a   Katayama, Hajime ^b  

^a SOOCHOW UNIVERSITY   (China)

^b KINJO GAKUIN UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

CUPROUS ION; DIOXANE; LIGAND; PHENYL GROUP; PYRAZOLE; PYRAZOLE DERIVATIVE; PYRAZOLO[1,5 A]INDOLE DERIVATIVE; SOLVENT; UNCLASSIFIED DRUG;

AMINATION; ARTICLE; CATALYSIS; CATALYST; CHEMICAL REACTION; DRUG STRUCTURE; DRUG SYNTHESIS; INTRAMOLECULAR AMINATION;

EID: 34547671144     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2007.07.033     Document Type: Article

References (18)

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15. 4. After filtration and evaporation of solvents, EtOH (50 mL) was added to the crude oil, and then 10 mL of AcOH and hydrazine monohydrate were added. The mixture was stirred for 10 min and the procedure of the reaction was exothermic reaction. Then the product was extracted with ethyl acetate and the extracts were washed with saturated sodium bicarbonate. 2d was obtained after silica gel chromatography.
16. 4 (anhydrous) and evaporated under reduced pressure. The resulting residue was isolated by chromatography (Silica Gel H 120 g, solvents: petroleum ether/ethyl acetate) to afford white solid 2.
17. 3 (345 mg, 2.5 mmol) were added to a solution of compound 2 (1.0 mmol) dissolved in anhydrous 1,4-dioxane (3 mL) in a pressure tube under the protection of Argon. The reaction mixture was stirred at 110 °C for 20 h and filtered through a pad of celite. After the removal of solvent under reduced pressure, the residue was purified by chromatography (Silica Gel H 10 g, solvents: petroleum ether/ethyl acetate) to give 3 as a solid.
18. 2O calcd, 262.1106; found, 262.1111.