Synlett, Inhaltsverzeichnis Synlett 2012; 23(19): 2850-2852DOI: 10.1055/s-0032-1317474 letter © Georg Thieme Verlag Stuttgart · New YorkEfficient One-pot Synthesis of 1H-Pyrazolo[1,5-b]indazoles by a Domino Staudinger–Aza-Wittig Cyclization Authors Institutsangaben Fen-Fen Zhao a Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079, P. R. of China Yan-Mei Yan a Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079, P. R. of China Rui Zhang b College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P. R. of China Fax: +86(27)67862041 eMail: mwding@mail.ccnu.edu.cn Ming-Wu Ding* a Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079, P. R. of China Artikel empfehlen Abstract Artikel einzeln kaufen(opens in new window) Alle Artikel dieser Rubrik(opens in new window) Abstract 1H-Pyrazolo[1,5-b]indazoles were prepared via a domino Staudinger–aza-Wittig cyclization in one-pot fashion, starting from easily accessible azides and triphenylphosphine. Key words Key words1H-pyrazolo[1,5-b]indazole - domino reaction - aza-Wittig reaction - azide - iminophosphorane Volltext Referenzen References and Notes 1a Tietze LF. Chem. Rev. 1996; 96: 115 1b Tietze LF, Brasche G, Gericke KM. Domino Reactions in Organic Synthesis . Wiley-VCH; Weinheim: 2006 2 Rodgers JD, Johnson BL, Wang H, Greenberg RA, Erickson Viitanen S, Klabe RM, Cordova BC, Rayner MM, Lam GN, Chang C.-H. Bioorg. Med. Chem. Lett. 1996; 6: 2919 3 Lee F.-Y, Lien J.-C, Huang L.-J, Huang T.-M, Tsai S.-C, Teng C.-M, Wu C.-C, Cheng FC, Kuo S.-C. J. Med. Chem. 2001; 44: 3746 4 Yakaiah T, Lingaiah BP. V, Narsaiah B, Shireesha B, Kumar BA, Gururaj S, Parthasarathy T, Sridhar B. Bioorg. Med. Chem. Lett. 2007; 17: 3445 5 Yakaiah T, Lingaiah BP. V, Narsaiah B, Kumar KP, Murthy US. N. Eur. J. Med. Chem. 2008; 341 6 Minu M, Thangadurai A, Wakode SR, Agrawal SS, Narasimhan B. Bioorg. Med. Chem. Lett. 2009; 19: 2960 7 Park JS, Yu KA, Yoon YS, Han MR, Kang TH, Kim S, Kim NJ, Yun H, Suh YG. Drugs Future 2007; 32: 121 8 Park JS, Yu KA, Kang TH, Kim S, Suh YG. Bioorg. Med. Chem. Lett. 2007; 17: 3486 9a Naganaboina VK, Chandra KL, Desper J, Rayat S. Org. Lett. 2011; 13: 3718 9b Kshirsagar UA, Puranik VG, Argade NP. J. Org. Chem. 2010; 75: 2702 9c Palacios F, Alonso C, Aparicio D, Rubiales G, Santos JM. Tetrahedron 2007; 63: 523 9d Alajarin M, Bonillo B, Ortin M.-M, Sanchez-Andrada P, Vidal A, Orenes R.-A. Org. Biomol. Chem. 2010; 8: 4690 9e Devarie-Baez NO, Xian M. Org. Lett. 2010; 12: 752 10 Molina P, Conesa C, Alías A, Arques A, Velasco MD. Tetrahedron 1993; 49: 7599 11a Xie H, Yuan D, Ding MW. J. Org. Chem. 2012; 77: 2954 11b Zhong Y, Wang L, Ding MW. Tetrahedron 2011; 67: 3714 11c He P, Nie YB, Wu J, Ding MW. Org. Biomol. Chem. 2011; 9: 1429 11d He P, Wu J, Nie YB, Ding MW. Eur. J. Org. Chem. 2010; 1088 11e Li WJ, Liu S, He P, Ding MW. Tetrahedron 2010; 66: 8151 11f Li WJ, Zhao FF, Ding MW. Synlett 2011; 265 11g Xie H, Yu JB, Ding MW. Eur. J. Org. Chem. 2011; 6933 11h Wu J, Liu JC, Wang L, Ding MW. Synlett 2011; 2880 11i Nie YB, Wang L, Ding MW. J. Org. Chem. 2012; 77: 696 12 General Procedure for the Preparation of Azides 5 To a mixture of piperidine (0.85 g, 10 mmol) and AcOH (0.6 g, 10 mmol) in EtOH (10 mL) at 0 °C was added 2-azidobenzaldehyde (1.32 g, 10 mmol) and ketone (10 mmol). After stirring for 1–2 h, the solvent was evaporated under vacuum, and the residue was recrystallized to give the azide 5. Compound 5a: light yellow solid (yield 89%), mp 75–76 °C. 1H NMR (600 MHz, CDCl3): δ = 7.80 (s, 1 H, =CH), 7.46–7.11 (m, 4 H, ArH), 4.30–4.25 (m, 2 H, OCH2), 2.45 (s, 3 H, CH3), 1.24–1.20 (m, 3 H, CH3) ppm. 13C NMR (150 MHz, CDCl3): d = 194.7, 167.1, 139.3, 136.2, 135.5, 131.6, 128.9, 124.6, 118.3, 61.5, 26.4, 13.7 ppm. MS (EI, 70 eV): m/z (%) = 259 (4) [M+], 231 (12), 217 (19), 203 (27), 143 (100), 115 (58). Anal. Calcd for C13H13N3O3: C, 60.22; H, 5.05; N, 16.21. Found: C, 60.01; H, 4.92; N, 16.02. 13 General Procedure for the Preparation of 9 To a solution of azide 5 (2 mmol) in dry toluene (10 mL) was added dropwise a solution of Ph3P (0.52 g, 2 mmol) in toluene (10 mL) at 0 °C. The reaction mixture was stirred for 2 h and then was refluxed for 2–8 h. The mixture was condensed, and the precipitate was collected or the residue was chromatographed (PE–Et2O, 4:1) on a silica gel column to give 1H-pyrazolo[1,5-b]indazole derivatives 9. Compound 9a: white solid (yield 90%); mp 193–194 °C. 1H NMR (600 MHz, CDCl3): δ = 12.0 (s, 1 H, NH), 8.27 (d, J = 7.8 Hz, 2 H, ArH), 7.54–7.32 (m, 4 H, ArH), 4.45 (q, J = 7.2 Hz, 2 H, OCH2), 2.67 (s, 3 H, CH3), 1.50 (t, J = 7.2 Hz, 3 H, CH3) ppm. 13C NMR (150 MHz, CDCl3): δ = 164.0, 152.7, 143.4, 135.5, 128.4, 123.0, 122.4, 116.2, 110.8, 100.2, 59.9, 14.8, 14.3 ppm. MS (EI, 70 eV): m/z (%) = 243 (39) [M+], 198 (10), 144 (100). Anal. Calcd for C13H13N3O2: C, 64.19; H, 5.39; N, 17.27. Found: C, 63.89; H, 5.22; N, 17.32. 14 Luheshi AB. N, Salem SM, Smalley RK. Tetrahedron Lett. 1990; 31: 6561 Zusatzmaterial Zusatzmaterial Supporting Information (PDF)
