Phosphorus sulfide (P2S5) → [5-Fluoro-2-(3-nitro-benzylthiocarbamoyl)-phenoxy]-acetic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

In a flame dried flask under a nitrogen atmosphere, a suspension of phosphorus pentasulfide (0.77 g, 1.73 mmol) in pyridine (6.9 mL) was treated with [5-fluoro-2-(3-nitro-benzylcarbamoyl)-phenoxy]-acetic acid ethyl ester (Example 27, 1.3 g, 3.45 mmol) and heated to 115° C. for 4 h. After cooling to room temperature, the mixture was diluted with water and ethyl acetate. The organic layer was washed successively with 2 N HCl and saturated NaCl, dried over MgSO4, and concentrated. The dark orange solid was filtered through a short pad of silica and again concentrated to give [5-fluoro-2-(3-nitro-benzylthiocarbamoyl)-phenoxy]-acetic acid ethyl ester as an orange solid (1.2 g, 89%): mp 118° C.; Rf 0.43 (40% ethyl acetate in heptane); 1H NMR (DMSO-d6 300 MHz) δ 10.71 (s, 1 H), 8.23 (s, 1 H), 8.12 (d, J=8.1 Hz, 1 H), 7.83 (d, J=7.8 Hz, 1 H), 7.71–7.60 (m, 2 H), 7.04 (dd, J1=11.1 Hz, J2=2.4 Hz, 1 H), 6.87 (dt, J1=8.4 Hz, J2=2.4 Hz, 1 H), 5.07 (d, J=3.3 Hz, 2 H), 4.89 (s, 2 H), 4.13 (q, J=6.7 Hz, 2 H), 1.17 (t, J=5.7 Hz, 3 H). ESI-LC/MS m/z calcd for C18H17FN2O5S: 394.1. Found 393.0 (M+1)+. Anal. calcd for C18H17FN2O5S: C, 55.09; H, 4.37; N, 7.14. Found C, 54.98; H, 4.36; N, 7.08.

Provenance & Evidence