Synthesis of substituted 2,3,5,6,7,8-hexahydropyrazolo[4,3- d][1,2]diazepine-8-carboxylates

• Published in: Tetrahedron Vol. 62; no. 34; pp. 8126 - 8132
• Main Authors: Bevk, David, Grošelj, Uroš, Meden, Anton, Svete, Jurij, Stanovnik, Branko
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 21.08.2006; Elsevier
• Subjects: 3-(Dimethylamino)propenoates; Chemistry; Chemistry, Organic; Heterocycles; Physical Sciences; Pyrazolo[4,3-d][1,2]diazepines; Science & Technology; Heterocycles; 3-(Dimethylamino)propenoates; Pyrazolo[4,3-d][1,2]diazepines; heterocycles; pyrazolo[4,3-d][1,2]diazepines; DIAZOALKANES; PYRAZOLINO-DIAZEPINES; STEREOSELECTIVE-SYNTHESIS; 3-(dimethylamino)propenoates; APLYSINOPSIN ANALOGS; TRANSFORMATIONS; ETHYL
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2006.06.002

Substituted 2,3,5,6,7,8-hexahydropyrazolo[4,3- d][1,2]diazepine-8-carboxylates were prepared in good to excellent yields from ethyl (2 E)-3-(dimethylamino)-2-{(4 Z)-4-[(dimethylamino)methylidene]-5-oxo-1-phenyl-4,5-dihydro-1 H-pyrazol-3-yl}propenoate with 1,2-disubstituted hydrazines by heating in an alcohol. Substituted 2,3,5,6,7,8-hexahydropyrazolo[4,3- d][1,2]diazepine-8-carboxylates were obtained from ethyl (2 E)-3-(dimethylamino)-2-{(4 Z)-4-[(dimethylamino)-methylidene]-5-oxo-1-phenyl-4,5-dihydro-1 H-pyrazol-3-yl}propenoate, via substitution of both dimethylamino groups with 1,2-dialkylhydrazines. [Display omitted]