反应详情

Sodium hydride powder (0.86 g, 35.8 mmol) was added to a mixture of 4-(4-chlorophenoxy)thiophenol (3.55 g, 15 mmol) in N,N-dimethylformamide (12 mL) at 0° C. The mixture was warmed to room temperature over 5 minutes, stirred for an additional 20 minutes, and solid chloropivalic acid (1.64 g, 12.0 mmol) was added in one portion. This mixture was heated to 80° C. for 18 hours, cooled to room temperature, and water (1 mL) added. The residue was partitioned between methylene chloride (50 mL) and 2N hydrochloric acid (25 mL). The aqueous layer was separated and washed with additional methylene chloride (2×25 mL). The combined organic extracts were dried over magnesium sulfate, concentrated in vacuo. Chromatography over silica gel, and eluting with 5% methanol/methylene chloride, gave slightly impure 3-[4-(4-chlorophenoxy)phenylthio]-2,2-dimethyl propionic acid (4 g, 99%). This material was recrystallized from the minimum amount of diethyl ether/hexanes to afford analytically pure acid as a white solid (3.20 g, 80%). mp 84.4-84.9° C.; IR (KBr) 3433 (br), 1732 cm-1 ; 1HNMR (DMSO-d6) δ 1.19 (s, 6H), 3.14 (s, 2H), 6.97 (d, J=8.7 Hz, 2H), 7.01 (d, J=8.9, 2H), 7.40 (d, J=8.8 Hz, 2H), 12.36 (br s, 1H). EIMS(M+): 378. Anal. Calcd. for C17H17SO3Cl: C, 60.62; H, 5.09. Found: C, 60.31; H, 4.96.

1. temperatureThis mixture was heated to 80° C. for 18 hours
2. temperaturecooled to room temperature
3. customThe residue was partitioned between methylene chloride (50 mL) and 2N hydrochloric acid (25 mL)
4. customThe aqueous layer was separated
5. washwashed with additional methylene chloride (2×25 mL)
6. dry with materialThe combined organic extracts were dried over magnesium sulfate
7. concentrationconcentrated in vacuo
8. washChromatography over silica gel, and eluting with 5% methanol/methylene chloride