Synlett 2004(10): 1735-1738  
DOI: 10.1055/s-2004-829565
LETTER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Phosphonic Acids with the Semicarbazide Group for the Functionalization of Metal Oxide and Zeolite Nanoparticles

Tristan Doussineau*a, Jean-Olivier Duranda, Michel Graniera, Monique Smaïhib, Valentin Valtchevc
a Chimie Moleculaire et Organisation du Solide, UMR 5637 cc 007 Université Montpellier, 2, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
Fax: +33(4)67143852; e-Mail: doussine@iemm.univ-montp2.fr;
b Institut Européen des Membranes, UMR 5635 cc 047 Université Montpellier, 2, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
c Laboratoire des Matériaux Minéraux, (LMM) UMR 7016, ENSCMu, 3 rue Alfred Werner, 68093 Mulhouse, France
Further Information

Publication History

Received 21 April 2004
Publication Date:
15 July 2004 (online)

Abstract

The syntheses of two phosphonic acids possessing the Fmoc-protected semicarbazide group are described. The key step was the Curtius rearrangement, performed in the presence of dibenzyl phosphonate esters. Preliminary experiments showed that the phosphonic acid can be grafted at the surface of oxide nanoparticles and colloidal zeolite nanocrystals, without deprotection of the Fmoc group.

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Experimental Procedure for 2b: KH 30% in mineral oil (4.0 g, 30.0 mmol) was suspended in dry DMF (150 mL) at 0 °C. Dibenzylphosphite (8.0 g, 30.0 mmol) was added dropwise. Methyl 11-bromo undecanoate (7.3 g, 26.1 mmol) was then rapidly added. The reaction was allowed to warm to r.t. after 15 min. After 6 h, the reaction was quenched at at 0 °C by careful addition of H2O (100 mL). The mixture was extracted with EtOAc (3 × 100 mL) and the organic phase washed with a minimum amount of H2O, dried over MgSO4, the solvents were then evaporated. Flash chromatography (Et2O) afforded 2b (8.94 g, 74%). 1H NMR (CDCl3): δ = 1.26-1.85 (m, 18 H, CH2), 2.34 (t, 2 H, 3 J H-H = 7.65 Hz), 3.70 (s, 3 H), 5.00 (m, 4 H), 7.38 (s, 10 H) ppm. 13C NMR (CDCl3): δ = 22.68 (td, 1 C, 2 J C-P = 5.28 Hz), 25.35 (t, 1 C), 26.42 (td, 1 C, 1 J C-P = 139.77 Hz), 29.39-29.74 (m, 5 C), 30.89 (td, 1 C, 3 J C-P = 17.06 Hz), 34.51 (t, 1 C), 51.85 (q, 1 C), 67.41 (td, 2 C, 3 J C-P = 6.46 Hz), 128.28 (d, 4 C), 128.73 (d, 2 C), 128.97 (d, 4 C), 136.97 (sd, 2 C, 3 J C-P = 5.94 Hz), 174.73 (s, 1 C, C=O) ppm. IR (NaCl pellets): ν (CHarom.) = 3090, 3064, 3033; ν (CH2aliph) = 2928, 2854; ν (C=Oester) = 1736 cm-1. MS (FAB+, NBA): m/z [MH+] = 461.

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Data for 5b: IR (KBr): ν (NH) = 3306; ν (CH arom) = 3063, 3038; ν (CH2) = 2922, 2850; ν (POH) = 3500-2500, 2347; ν (C=O) = 1731; ν (C=O) = 1661; δ (NH) = 1556; ν (P=O) 1264 and 1217, 1157, 1098, 898, 759, 738 cm-1. 1H NMR (CDCl3, 1 drop of TFA: δ = 1.30-1.60 (m, 16 H), 1.88-2.04 (m, 2 H), 3.22 (t, 3 J = 6.90 Hz, 2 H), 4.26 (t, 3 J = 5.80 Hz, 1 H), 4.70 (d, 3 J = 5.80 Hz, 2 H), 7,35-7.48 (m, 4 H), 7,55 (d, 3 J = 7.40 Hz, 2 H), 7.81 (d, 3 J = 7.33 Hz, 2 H) ppm. 13C NMR (DMSO): δ = 23.62 (td, 1 C, 2 J C-P = 4.19 Hz), 28.82 (td,1 C, 1 J C-P = 178.63 Hz), 29.58-29,90 (m, 7 C, CH2), 30.98 (td, 1 C, 3 J C-P = 16.17 Hz), 47.42 (t, 1 C), 67.00 (d, 1 C), 120.97 (d, 2 C), 126.23 (d, 2 C), 127.98 (d, 2 C), 128.56 (d, 2 C), 141.57 (s, 2 C), 144.53 (s, 2 C), 157.71 (s, 1 C, C=O), 159.10 (s, 1 C, C=O) ppm. 31P NMR (DMSO): δ = 24.97 ppm. MS (ES+, Q-TOF): m/z [(M - H + Na) + H+] = 540.3.