An Efficient Synthesis of 3‐(1H‐Tetrazol‐5‐yl)coumarins (=3‐(1H‐Tetrazol‐5‐yl)‐2H‐1‐benzopyran‐2‐ones) via Domino Knoevenagel Condensation, Pinner Reaction, and 1,3‐Dipolar Cycloaddition in Water

A novel straightforward synthesis of 3-(1H-tetrazol-5-yl)coumarins (=3-(1H-tetrazol-5-yl)-2H-1-benzopyran-2-ones) 6 via domino Knoevenagel condensation, Pinner reaction, and 1,3-dipolar cycloaddition of substituted salicylaldehydes (=2-hydroxybenzaldehydes), malononitrile (propanedinitrile), and sodium azide in H2O is reported (Scheme 1 and Table 2). This general protocol provides a wide variety of 3-(1H-tetrazol-5-yl)coumarins in good yields under mild reaction conditions.

[1]  N. Pokhodylo,et al.  Synthesis of 6-(5-sulfanyl-1H-tetrazol-1-yl)-2H-chromen-2-one and 5-methyl-1-(2-oxo-2H-chromen-6-yl)-1H-1,2,3-triazole-4-carboxylic acid , 2010 .

[2]  W. Liu,et al.  Mesoporous ZnS nanospheres: a high activity heterogeneous catalyst for synthesis of 5-substituted 1H-tetrazoles from nitriles and sodium azide. , 2010, Chemical communications.

[3]  Dominique Roberge,et al.  Synthesis of 5-substituted 1H-tetrazoles from nitriles and hydrazoic acid by using a safe and scalable high-temperature microreactor approach. , 2010, Angewandte Chemie.

[4]  M. Krishnaiah,et al.  A Simple, Advantageous Synthesisof 5-Substituted 1H-Tetrazoles , 2010 .

[5]  M. Nasrollahzadeh,et al.  FeCl3–SiO2 as a reusable heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles via [2+3] cycloaddition of nitriles and sodium azide , 2009 .

[6]  A. Majee,et al.  Indium triflate-catalyzed one-pot synthesis of 1-substituted-1H-1,2,3,4-tetrazoles under solvent-free conditions , 2009 .

[7]  C. Bolm,et al.  Iron salts in the catalyzed synthesis of 5-substituted 1H-tetrazoles. , 2009, Chemistry.

[8]  A. Chaskar,et al.  Synthesis and Antibacterial Activity of New Tetrazole Derivatives , 2008 .

[9]  A. Katritzky,et al.  Efficient Synthesis of 1,5-Disubstituted Tetrazoles , 2007 .

[10]  T. M. Potewar,et al.  Efficient and rapid synthesis of 1 -substituted -1H-1,2,3,4-tetrazoles in the acidic ionic liquid 1-n-butylimidazolium tetrafluoroborate , 2007 .

[11]  B. Schmidt,et al.  Safe and fast tetrazole formation in ionic liquids , 2007 .

[12]  Yoshinori Yamamoto,et al.  Synthesis of 1-substituted tetrazoles via the acid-catalyzed [3+2] cycloaddition between isocyanides and trimethylsilyl azide , 2004 .

[13]  Shane M. Devine,et al.  Synthesis and reactivity of some imidazo‐, triazolo‐ and tetrazolo‐isoquinoline derivatives , 2004 .

[14]  H. Drexler,et al.  Therapeutic Effects of Angiotensin (AT1) Receptor Antagonists , 2004, American journal of cardiovascular drugs : drugs, devices, and other interventions.

[15]  B. Schmidt,et al.  Angiotensin II AT1 receptor antagonists. Clinical implications of active metabolites. , 2003, Journal of medicinal chemistry.

[16]  R. Orita,et al.  Novel Synthesis of 5-Substituted Tetrazoles from Nitriles , 1998 .

[17]  K Prendergast,et al.  Nonpeptide angiotensin II receptor antagonists: the next generation in antihypertensive therapy. , 1996, Journal of medicinal chemistry.

[18]  F. A. Amer,et al.  A facile and convenient synthesis of substituted tetrazole derivatives from ketones or α,β-unsaturated ketones , 1995 .

[19]  P. Magnus,et al.  Mild regiospecific rearrangement of α,β-unsaturated ketones into ring expanded annulated tetrazoles , 1991 .

[20]  A. Nohara.  Synthesis of 3-(1H-tetrazol-5-YL)chromones and a novel degradation reaction of tetrazole ring with vilsmeier reagents , 1974 .

[21]  J. Sauer,et al.  Zur acylierung von 5-aryl-tetrazolen; ein duplikationsverfahren zur darstellung von polyarylen☆ , 1960 .