5-CHLORO-1-(2,6-DICHLOROBENZYL)-1H-INDOLE-2,3-DIONE synthesis

Yield:252579-05-8 84%

Reaction Conditions:

with 1,8-diazabicyclo[5.4.0]undec-7-ene in ethanol at 120; for 0.333333 h;Microwave irradiation;

Steps:

To a 10 mL microwave vial chargedwith ethanol (3 mL) a magnetic stir bar was added 5-chloroisatin (0.3658 g, 2.01 mmol), DBU(329 μL, 1.1 eq) and 2,6-dichlorobenzyl bromide (0.5310 g, 1.1 eq). The reaction vessel wassealed and heated under microwave irradiation in standard mode for 20 min at 120 ^oC with a prestirring30 sec. After cooling to rt, the reaction vessel was placed in the freezer for 2 h and thenvacuum filtered to afford the pure (TLC, GC/MS) product as an orange-red solid (0.5772 g,84%): mp 232-235 C (lit.14mp 233-235 oC); Rf = 0.60 (hexanes/EtOAc, 1:1). 1H NMR (300MHz DMSO-d6) δ 7.73 ppm (dd, J = 8.5 Hz, 2.3 Hz, 1H), 7.65 (d, J = 2.3 Hz, 1H), 7.55 (d, J =8.0 Hz, 1H), 7.44 (t, 7.9 Hz, 1H), 7.01 (d, J = 8.4 Hz, 1H), 5.12 (s, 2H); 13C NMR (75 MHzDMSO-d6) δ 181.6, 157.5, 149.2, 137.3, 135.4, 130.8, 129.5, 129.1, 127.6, 124.2, 118.9, 112.6,40.4; MS (m/z) 339 (M+), 180 (100%).

References:

Jordan, Carly A.;Wieczerzak, Krystyna B.;Knisley, Kyle J.;Ketcha, Daniel M. [ARKIVOC,2014,vol. 2014,# 4,p. 183 - 192]