Download PDF
Synlett 2011(17): 2509-2512  
DOI: 10.1055/s-0030-1260323
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Efficient Preparation of ortho-Aminobenzenesulfonamides using Ligand-Free Copper(I)-Catalyzed Amination

Zineb Bahlaouana, Jérôme Thibonneta, Alain Duchênea, Jean-Luc Parrainb, Mostafa Elhilalia, Mohamed Abarbri*a
a Laboratoire de Physicochimie des Matériaux et Biomolécules, EA 4244, Université François Rabelais, Faculté des Sciences, Parc de Grandmont, 37200 Tours, France
Fax: +33(2)47367073; e-Mail: mohamed.abarbri@univ-tours.fr;
b Institut des Sciences Moléculaires de Marseille, iSm2 UMR CNRS 6263, Campus Scientifique de Saint Jérôme, Aix-Marseille Université, 13397 Marseille, France
Further Information

Publication History

Received 10 June 2011
Publication Date:
22 September 2011 (online)

    Permissions and Reprints All articles of this category

Abstract

A general and efficient method of copper-catalyzed amination of 2-iodobenzenesulfonamide has been developed under very mild conditions, with good to excellent yields. This method uses inexpensive copper(I) iodide as catalyst, readily available 2-iodobenzenesulfonamides and aliphatic amines as the starting materials, and does not require the use of any ligand system or any expensive supplementary additives.

Key words

2-iodobenzenesulfonamide - copper(I) catalyst - N-arylation - ligand-free - 2-aminobenzenesulfonamides

20

Typical Experimental Procedure for the Synthesis of N -Benzyl-2-(propargylamino)benzenesulfonamide (2c): 2-Iodobenzenesulfonamide (300 mg, 1 mmol), K2CO3 (138 mg, 1 mmol) and anhyd DMF (10 mL) were introduced into a dry Schlenk flask under argon. The mixture was cooled to 0 ˚C and degassed under agitation (10 min). Then amine (1.1 mmol) and CuI (19 mg, 0.1 mmol) were introduced successively under argon flux. The mixture was brought to r.t. and left under stirring for 12 h. The reaction mixture was diluted with Et2O, washed with aq NH4Cl and H2O, dried over MgSO4, filtered and concentrated under vacuum. The residue was purified by chromatography on silica gel (petroleum ether-Et2O, 50:50) or by crystallization (petroleum ether-CH2Cl2, 80:20); yield: 79%; white solid; mp 64-66 ˚C. IR (KBr): 1599, 2114, 2963, 3252, 3389 cm-¹. ¹H NMR (200 MHz, CDCl3): δ = 7.79 (dd, J = 7.9, 1.3 Hz, 1 H), 7.47 (td, J = 7.9, 1.3 Hz, 1 H), 7.13-7.26 (m, 5 H), 6.79-6.91 (m, 2 H), 6.06 (t, J = 5.4 Hz, 1 H), 5.25 (t, J = 6.2 Hz, 1 H), 3.94-4.06 (m, 4 H), 2.24 (t, J = 2.4 Hz, 1 H). ¹³C NMR (50 MHz, CDCl3): δ = 144.2, 139.4, 135.7, 134.0, 129.8, 128.2 (2 × C), 127.4 (2 × C), 121.4, 116.9, 112.6, 79.5, 71.4, 46.8, 32.4. MS (EI): m/z = 300 [M] (8), 130 (51), 129 (59), 108, 106 (100), 102 (22), 91 (63). Anal. Calcd for C16H16N2O2S: C, 63.98; H, 5.37; N, 9.33. Found: C, 63.83; H, 5.41; N, 9.35.