Hydrochloric Acid → HCID 67175712, compound

Participants

Reaction Steps

Mechanically stir solutions of 1-(2,4-dihydroxy-3-trifluoromethyl-phenyl)-2-methyl-propan-1-one (211 g, 850.1 mmol), (4-hydroxymethyl-benzyl)-carbamic acid tert-butyl ester (195 g, 821.8 mmol), and triphenylphosphine (212 g; 808.3 mmol) in toluene (9 L) in two separate 22-L Morton flasks. Treat solutions with diisopropyl azodicarboxylate (183 mL, 923 mmol) over a 60 min period, then stir over the weekend at room temperature. Combine the solutions and evaporate to a brown oil. Dissolve the oil in 1,4-dioxane (8 L), treat with 4N hydrogen chloride solution in 1,4-dioxane (3 L, 12 mole), and heat to 92° C. for 6 hrs (out-gassing and precipitation is observed at 52° C. during the warm up period). Cool to room temperature, filter the resulting solid and wash with dioxane, 30% dioxane in hexanes, and hexanes to provide the title compound (510 g, 78% yield) as a tan solid. HPLC Rt=4.71 min; 1H NMR (DMSO-d6) δ 14.00 (s, 1H), 8.4 (bs, 3H), 7.50 (ABq, J=12.0, 8.0 Hz, 4H), 6.92 (d, J=8.0 Hz, 1H), 5.37 (s, 2H), 4.0 (m, 2H), 3.73 (hept, J=4.0 Hz, 1H), 1.12 (d, J=4.0 Hz, 6H); 19F NMR (DMSO-d6) δ-54.10; MS (m/z): 368.0 (M+1).

Provenance & Evidence