16. The sulfenylating agent 4c (100 mg, 0.148 mol) was dissolved in DMF (2 mL), and NaHCO,(29 mg, 0.35 mmol) was added with stirring. No obvious reaction occurred (no color change). Water (5 mL) was added, and the precipitate that formed was filtered off, washed with water, and dried to yield crude 16 (60 mg). Preparative TLC (CH2C12 as eluant) yielded 16, 50 mg (82%). Recrystallization (CHCl,/MeCN) yielded 20 mg 16 mp 170-173" ...
