Dabco → HCID 20087903, compound

Participants

Reaction Conditions

Reaction Steps

Sulfuryl chloride (0. 305 ml, 3.78 mmole, 1.0 equiv.) was added dropwise over 3 min to a suspension of 6-chloro-2-[2-[(phenylmethyl)thio]phenyl]-4(1H)-quinolinone (1.43 g, 3.78 mmole, 1 equiv.) in dry, EtOH-free CHCl3 (190 ml) at -15° C. The mixture was stirred for 0.5 hr, then was heated to reflux After 20 min, the reaction was cooled to 25° C., and 1,4-diazabicyclo[2.2.21octane (636 mg, 5.67 mmole, 1.5 equiv.) was added. The nearly homogeneous solution was stirred at 25° C. for an additional 5 min, then was washed with H2O (3×50 ml). The combined aqueous layers, which contained suspended product, were back-extracted with CHCl3, and the combined organic layers were diluted with CHCl3 (200 ml) and MeOH (50 ml) to dissolve suspended solids. Drying (MgSO4), concentration, and silica gel chromatography (CHCl3, then 10% MeOH in 50% EtOAc/CHCl3, then 10% MeOH/CHCl3) gave 3-chloro-5H-[1,2]benzisothiazolo [2,3-a]quinoline-5-one (0.28 g, 26%) as a yellow solid. Two recrystallizations from CHCl3 /EtOAc gave yellow, very fine needles: mp>350° C.; TLC (5% MeOH in 50% EtOAc/CHCl3) Rf 0.32; 1H NMR (CDCl3) δ8.52 (d, J=2.2 Hz, 1H), 8.00 (app d, 1H), 7.62-7.74 (m, 3H), 7.50-7.60 (m, 1H), 7.44 (d, J=8.8 Hz, 1H), 7.08 (s, 1H); IR (KBr) 1613, 1587, 1567, 1554, 1539, 1461, 1450 cm-1 ; MS (NH3), m/e (%) 288 (41, (37Cl M+H)+), 286 (100, (35Cl M+H)+). Anal. Calcd for C15H8ClNOS: C, 63.05; H, 2.82; N, 4.90. Found: C, 62.83; H, 2.51; N, 4.75.

Provenance & Evidence