4-Toluenesulfonyl chloride → tert-butyl 3-(3-iodo-1-tosyl-1H-indol-5-yl)-1,2,4-thiadiazol-5-ylcarbamate

Participants

Reaction Steps

To a solution of tert-butyl (3-(3-iodo-1H-indol-5-yl)-1,2,4-thiadiazol-5-yl)carbamate (80 mg, 0.18 mmol) in DMF (2.5 mL) at 0° C. was added 60% NaH (80 mg, 0.199 mmol) at 0° C. and the reaction was stirred at RT. After 5 min, the mixture was again cooled to 0° C. and 4-methylbenzene sulfonyl chloride (38 mg, 0.199 mmol) in DMF (2.5 mL) was added dropwise. The reaction was stirred at RT for 1 h, then treated with ice cold water (5 mL) and extracted with EtOAc (10 mL). The aqueous layer was back extracted with EtOAc (10 mL). The combined organic layers were dried over anhydrous Na2SO4 and concentrated. The crude was purified by silica-gel column Chromatography (eluent: 15% EtOAc in petroleum ether) to give tert-butyl (3-(3-iodo-1-tosyl-1H-indol-5-yl)-1,2,4-thiadiazol-5-yl)carbamate (50 mg, 46.7%) as an off white solid. MS (ESI, pos. ion) m/z: 540.9 (M+1) (carbamic acid mass). 1H NMR (400 MHz, DMSO-d6) δ 12.45 (brs, 1H), 8.22-8.19 (m, 1H), 8.15 (s, 1H), 8.11-8.07 (m, 2H), 7.95 (d, J=8.4 Hz, 2H), 7.41 (d, J=8 Hz, 2H), 2.31 (s, 3H), 1.51 (s, 9H).

Provenance & Evidence