diethyl benzylphosphonate

Chemical Properties

CLEAR COLOURLESS TO SLIGHTLY YELLOW LIQUID

Uses

Reactant for synthesis of:
    3,5-dihydroxy-4-isopropylstilbene for treatment of skin disorders
    Natural cytotoxic marine products of polyketide origin via intramolecular Diels-Alder reactions
    Stilbenes via on-column oxidation of vicinal diols and Horner-Emmons reactions
    Inhibitors of teh Wnt pathway for colon cancer repression using Wadsworth-Emmons reactions
    Antimalarial drug analogs against P. falciparum

Reactant for:
Cyclization of aryl ethers, amines, and amides
Investigating the effects of functional groups on the performance of clue organic LEDs

Uses

Diethyl benzylphosphonate is used as a reactant for synthesis of 3,5-dihydroxy-4-isopropylstilbene for treatment of skin disorders and natural cytotoxic marine products of polyketide origin via intramolecular Diels-Alder reactions. It is also used as reactant for cyclization of aryl ethers, amines and amides & for investigating the effects of functional groups on the performance of clue organic LEDs.

Preparation

Diethyl benzylphosphonate was synthesized according to the previously published procedure [1]. Benzylphosphonic acid (1 mmol, 172 mg) and triethyl orthoacetate (30 mmol, 5.5 mL) were mixed overnight at 90 °C. The completion of the reaction was monitored by 31P NMR. After the completion of the reaction, an excess of the orthoester was evaporated under reduced pressure. The crude product was purified via a short silica gel column (hexanes/ethyl acetate). The compound 1 was isolated as a transparent oil with 98% yield (0.98 mmol, 224 mg). 1H NMR (400 MHz, DMSO-d6) δ 7.39–7.14 (m, 5H), 3.94 (dq, JH-P = 7.9, JH-H = 7.0, 4H), 3.21 (d, JH-P = 21.6 Hz, 2H), 1.16 (t, JH-H = 7.0 Hz, 6H); 13C NMR (101 MHz, DMSO-d6) δ 132.3 (d, JC-P = 9.0 Hz), 129.7 (d, JC-P = 6.6 Hz), 128.2 (d, JC-P = 3.0 Hz), 126.4 (d, JC-P = 3.4 Hz), 61.3 (d, JC-P = 6.5 Hz), 32.3 (d, JC-P = 135.1 Hz), 16.1 (d, JC-P = 5.8 Hz); 31P NMR (162 MHz, DMSO-d6) δ 26.5. The NMR data are in accordance with those reported in literature [2].

Synthesis Reference(s)

Tetrahedron Letters, 29, p. 1513, 1988 DOI: 10.1016/S0040-4039(00)80339-1
Synthesis, p. 222, 1981 DOI: 10.1055/s-1981-29393

References

[1] DAMIAN TRZEPIZUR. Selective Esterification of Phosphonic Acids.[J]. Molecules, 2021. DOI:10.3390/molecules26185637.
[2] PETER J. THORNTON. Nucleoside Phosphate and Phosphonate Prodrug Clinical Candidates[J]. Journal of Medicinal Chemistry, 2016, 59 23: 10400-10410. DOI:10.1021/acs.jmedchem.6b00523.
[3] GASTON LAVEN. ChemInform Abstract: Preparation of Benzylphosphonates via a Palladium(0)-Catalyzed Cross-Coupling of H-Phosphonate Diesters with Benzyl Halides. Synthetic and Mechanistic Studies.[J]. ChemInform, 2010, 41 40. DOI:10.1002/chin.201040191.
[4] ANNA BRODZKA. The Synthesis and Evaluation of Diethyl Benzylphosphonates as Potential Antimicrobial Agents.[J]. Molecules, 2022. DOI:10.3390/molecules27206865.