Synlett 2018; 29(14): 1867-1870
DOI: 10.1055/s-0037-1609906
letter
© Georg Thieme Verlag Stuttgart · New York

Highly Efficient Coupling of Unstable Bicyclic Pyrimidines and Pyrazoles under Basic Conditions, and its Application to the Synthesis of Pharmaceutical Compounds

Takashi Goi*
a   Research Unit/Immunology & Inflammation, Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan   Email: goi.takashi@mk.mt-pharma.co.jp
b   Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043, Japan
,
Koichi Fukase
b   Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043, Japan
› Author Affiliations
This research was supported by Mitsubishi Tanabe Pharma Corporation, JSPS KAKENHI Grant Number 15H05836 (KF) in Middle Molecular Strategy, and JSPS KAKENHI Grant Number 16H01885 (KF).
Further Information

Publication History

Received: 10 May 2018

Accepted after revision: 12 June 2018

Publication Date:
31 July 2018 (online)


Abstract

The efficient Pd-catalyzed coupling of unstable bicyclic pyrimidines and pyrazoles under basic conditions was established for the first time. The reactions proceeded with excellent yields without hydrolysis using Pd2(dba)3, t BuXPhos, and K3PO4.

Supporting Information

 
  • References and Notes

    • 2a Joseph TM. WO 2017059191, 2017
    • 2b Nancy-Ellen H. WO 2013182580, 2013
  • 3 Nakai T. WO 2014047325, 2014
  • 5 Wolfe JP. Buchwald SL. Tetrahedron Lett. 1997; 38: 6359
  • 6 Huang X. Anderson KW. Zim D. Jiang L. Klapars A. Buchwald SL. J. Am. Chem. Soc. 2003; 125: 6653
  • 7 Mauger C. Mignani G. Adv. Synth. Catal. 2005; 347: 773
  • 8 Anderson KW. Tundel RE. Ikawa T. Altman RA. Buchwald SL. Angew. Chem. Int. Ed. 2006; 45: 6523
  • 9 Surry DS. Buchwald SL. Angew. Chem. Int. Ed. 2008; 47: 6338
  • 10 Experimental Procedure for Synthesizing 8 A mixture of bicyclic pyrimidine 7 (100 mg, 0.328 mmol), pyrazole 9 (55 mg, 0.394 mmol), Pd2(dba)3 (15 mg, 0.0164 mmol), t BuXPhos (14 mg, 0.0328 mmol), and K3PO4 (105 mg, 0.492 mmol) in t BuOH (3 mL) was stirred at 80 °C for 15 h under a nitrogen atmosphere. After the mixture was cooled to ambient temperature, water was added, and the mixture was extracted with chloroform twice. The organic layers were combined and concentrated under reduced pressure to give the crude product. The residue was purified by NH silica gel column chromatography to afford 8 (101 mg, 75%) as a colorless solid. 1H NMR (400 MHz, CDCl3): δ = 9.03 (d, J = 1.0 Hz, 1 H), 8.17 (s, 1 H), 8.16 (s, 1 H), 7.26–7.23 (m, 2 H), 6.86–6.83 (m, 2 H), 5.67 (s, 2 H), 4.36 (q, J = 7.2 Hz, 2 H), 4.33 (s, 3 H), 3.77 (s, 3 H), 1.39 (t, J = 7.2 Hz, 3 H). 13C NMR (100 MHz, CDCl3): δ = 162.8, 159.5, 157.3, 148.9, 146.6, 143.5, 133.8, 132.5, 129.2, 128.5, 120.3, 117.1, 114.2, 60.6, 55.4, 55.3, 55.0, 14.4. HRMS (ESI): m/z calcd for C20H21O4N6 [M + H]+: 409.1619; found: 409.1609.
  • 11 Burgos CH. Barder TE. Huang X. Buchwald SL. Angew. Chem. Int. Ed. 2006; 45: 4321
  • 12 Dooleweerdt K. Fors BP. Buchwald SL. Org. Lett. 2010; 12: 2350
  • 13 Valente C. Çalimsiz S. Hoi KH. Mallik D. Sayah M. Organ MG. Angew. Chem. Int. Ed. 2012; 51: 3314
  • 14 Nakajima T. Goi T. Kawata A. Sugahara M. Yamakoshi S. WO 2014030716, 2014