Fe(ClO₄)₃·H₂O-Catalyzed Ritter Reaction: A Convenient Synthesis of Amides from Esters and Nitriles

Abstract

An efficient and inexpensive synthesis of N-substituted amides from the Ritter reaction of nitriles with esters catalyzed by Fe(ClO₄)₃·H₂O is described. Fe(ClO₄)₃·H₂O is an economically efficient catalyst for the Ritter reaction under solvent-free conditions. Reactions of a range of esters (benzyl, sec-alkyl, and tert-butyl esters) with nitriles (primary, secondary, tertiary, and aryl nitriles) were performed to provide the corresponding amides in high to excellent yields.

Key words

Ritter reaction - Fe(ClO₄)₃·H₂O - esters - nitriles - solvent-free reactions

• References and Notes

• 1 Singh GS. Tetrahedron 2003; 59: 7631
• 2 Allen CL. Williams JM. J. Chem. Soc. Rev. 2011; 40: 3405
• 3 Valeur E. Bradley M. Chem. Soc. Rev. 2009; 38: 606
• 4a Saxo E. Bertozzi CZ. Science 2000; 287: 2007
• 4b Damkaci F. De Shong P. J. Am. Chem. Soc. 2003; 125: 4408
• 4c Gololobov YG. Kasukhin LF. Tetrahedron 1992; 48: 1353
• 5a Ribelin T. Katz CE. English DG. Smith S. Manukyan AK. Day VW. Neuenswander B. Poutsma JL. Aube J. Angew. Chem. Int. Ed. 2008; 47: 6233
• 5b Lang S. Murphy JA. Chem. Soc. Rev. 2006; 35: 146
• 6a Owston NA. Parker AJ. Williams JM. J. Org. Lett. 2007; 9: 3599
• 6b Hashimoto M. Obora Y. Sakaguchi S. Ishii Y. J. Org. Chem. 2008; 73: 2894
• 7a Chang JW. W. Ton TM. U. Tania S. Taylor PC. Chan PW. H. Chem. Commun. 2010; 46: 922
• 7b Ton TM. U. Tejo C. Tania S. Chang JW. W. Chan PW. H. J. Org. Chem. 2011; 76: 4894
• 7c Ghosh SC. Ngiam JS. Y. Chai CL. L. Seayad AM. Dang TT. Chen A. Adv. Synth. Catal. 2012; 354: 1407
• 7d Ghosh SC. Ngiam JS. Y. Seayad AM. Tuan DT. Chai CL. L. Chen A. J. Org. Chem. 2012; 77: 8007
• 7e Goh KS. Tan C.-H. RSC Adv. 2012; 2: 5536
• 7f Liu X. Jensen KF. Green Chem. 2012; 14: 1471
• 7g Li G.-L. Kung KK.-Y. Wong M.-K. Chem. Commun. 2012; 48: 4112
• 7h Zhu M. Fujita K.-i. Yamaguchi R. J. Org. Chem. 2012; 77: 9102
• 7i Krabbe SW. Chan VS. Franczyk TS. Shekhar S. Napolitano J. Presto CA. Simanis JA. J. Org. Chem. 2016; 81: 10688
• 8 Jiang D. -H. He T. Ma L. Wang Z.-Y. RSC Adv. 2014; 4: 64936
• 9 Firouzabadi H. Sardarian AR. Badparva H. Synth. Commun. 1994; 24: 601
• 10 Barbero M. Bazzi S. Cadamuro S. Dughera S. Eur. J. Org. Chem. 2009; 430
• 11 Theerthagiri P. Lalitha A. Arunachalam PN. Tetrahedron Lett. 2010; 51: 2813
• 12 Anxionnat B. Guérinot A. Reymond S. Cossy J. Tetrahedron Lett. 2009; 50: 3470
• 13 Mukhopadhyay M. Reddy MM. Maikap GC. Iqbal J. J. Org. Chem. 1995; 60: 2670
• 14 Lakouraj MM. Movassagh B. Fasihi J. Synth. Commun. 2000; 30: 821
• 15 Sanz R. Martínez A. Guilarte V. Álvarez-Gutiérrez JM. Rodríguez F. Eur. J. Org. Chem. 2007; 4642
• 16 Shakeri MS. Tajik H. Niknam K. J. Chem. Sci. 2012; 124: 1025
• 17 Karimian E. Akhlaghinia B. Ghodsinia SS. E. J. Chem. Sci. 2016; 128: 429
• 18 Posevins D. Suta K. Turks M. Eur. J. Org. Chem. 2016; 1414
• 19 Katkar KV. Chaudhari PS. Akamanchi KG. Green Chem. 2011; 13: 835
• 20 Khalafi-Nezhad A. Foroughi HO. Doroodmandab MM. Panahi F. J. Mater. Chem. 2011; 21: 12842
• 21 Zhao X.-N. Hu H.-C. Zhang F.-J. Zhang Z.-H. Appl. Catal. A.: Gen. 2014; 482: 258
• 22 Khaksar S. Fattahi E. Fattahi E. Tetrahedron Lett. 2011; 52: 5943
• 23 Qu G.-R. Song Y.-W. Niu H.-Y. Guo H.-M. John S.-F. RSC Adv. 2012; 2: 6161
• 24 Mokhtary M. Najafizadeh F. E-J. Chem. 2012; 9: 576
• 25 Mokhtary M. Goodarzi G. Chin. Chem. Lett. 2012; 23: 293
• 26 Tamaddon F. Tavakoli F. J. Mol. Catal. A.: Chem. 2011; 337: 52
• 27 Baum JC. Milne JE. Murry JA. Thiel OR. J. Org. Chem. 2009; 74: 2207
• 28 Nasr-Esfahani M. Montazerozohori M. Karami Z. Org. Prep. Proced. Int. 2016; 48: 321
• 29 Hanzawa Y. Kasashima Y. Tomono K. Mino T. Sakamoto M. Fujita T. J. Oleo. Sci. 2012; 61: 393
• 30 Typical Experimental Procedure for the Reaction of Benzonitrile and Esters (Benzyl, sec-Alkyl and Primary Alkyl Esters) A mixture of benzonitrile (5 mmol), benzyl acetate (6 mmol), and Fe(ClO₄)₃·H₂O (5 mol%) was placed in a round-bottomed flask. Then, the reaction mixture was heated at 80 °C for 5 h. After completion of the reaction monitored by thin layer chromatography (TLC), water (10 mL) was added, and the reaction mixture was extracted with ethyl acetate (3 × 20 mL). The organic layers were collected, combined, washed with water (3 × 20 mL), dried with anhydrous Na₂SO₄, and concentrated under vacuum. The pure product was obtained by directly passing through a silica gel (200–300 mesh) column to give a white powder a (0.91 g, 87% yield). Compound a ¹H NMR (CDCl₃, 400 MHz): δ = 7.80 (m, 2 H), 7.78–7.25 (m, 8 H), 6.51 (s, 1 H), 4.64 (d, J = 5.8 Hz, 2 H) ppm. ¹³C NMR (CDCl₃, 100 MHz): δ = 167.4, 138.2, 134.4, 131.6, 128.8, 128.6, 127.9, 127.6, 127.0, 44.1 ppm.
• 31 Typical Experimental Procedure for the Reaction of Various Nitriles and Acetic Esters A mixture of 3-methylbenzonitrile (5 mmol), benzyl acetate (6 mmol), and Fe(ClO₄)₃·H₂O (5 mol%) was placed in a round-bottomed flask. Then, the reaction mixture was heated at 80 °C for 5 h. After completion of the reaction monitored by thin layer chromatography (TLC), water (10 mL) was added, and the reaction mixture was extracted with ethyl acetate (3 × 20 mL). The organic layers were collected, combined, washed with water (3 × 20 mL), dried with anhydrous Na₂SO₄, and concentrated under vacuum. The pure product was obtained by directly passing through a silica gel (200–300 mesh) column to give a white powder n (0.96 g, 86% yield). Compound n ¹H NMR (CDCl₃, 400 MHz): δ = 7.61–7.55 (m, 2 H), 7.34–7.28 (m, 7 H), 6.55 (s, 1 H), 4.62 (d, J = 5.64 Hz, 2 H), 2.37 (s, 3 H) ppm. ¹³C NMR (CDCl₃, 100 MHz): δ = 167.6, 138.4, 138.3, 134.3, 132.3, 128.8, 128.4, 127.9, 127.7, 127.6, 123.9, 44.1, 21.3 ppm.
• 32 Typical Experimental Procedure for the Reaction of Nitriles and di-tert-Butyl Malonate A mixture of 2-(3, 4-dichlorophenyl)acetonitrile (5 mmol), di-tert-butyl malonate (3 mmol), and Fe(ClO₄)₃·H₂O (5 mol%) was placed in a round-bottomed flask. Then, the reaction mixture was heated at 80 °C for 5 h. After completion of the reaction monitored by thin layer chromatography (TLC), water (10 mL) was added and the reaction mixture was extracted with ethyl acetate (3 × 20 mL). The organic layers were collected, combined, washed with water (3 × 20 ml), dried over anhydrous Na₂SO₄, and concentrated under vacuum. The pure product was obtained by directly passing through a silica gel (200–300 mesh) column to give a white powder 1m (1.08 g, 84% yield). Compound 1m ¹H NMR (400 MHz, CDCl₃): δ = 7.41–7.35 (m, 2 H), 7.12–7.10 (m, 1 H), 5.31 (s, 1 H), 3.40 (s, 2 H), 1.32 (s, 9 H) ppm. ¹³C NMR (100 MHz, CDCl₃): δ = 168.9, 135.6, 132.7, 131.2, 131.2, 130.6, 128.6, 51.6, 43.5, 28.7 ppm. HRMS: m/z calcd for C₁₂H₁₅Cl₂NO [M + H]⁺: 259.0531; found: 259.0533.