3-(1H-pyrrol-2-ylmethylidene)-1H-indol-2-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (NH4)2SO4 (0.09 g, 0.67 mmol) was added into a stirred mixture of 8 (1.0 g, 6.61 mmol) in HMDS (20 mL, 20 P) at room temperature. The reaction mixture was then heated to reflux and maintained at that temperature for no less than 5 hours. Monitor the reaction by GC. After the reaction is completed, 14 (1.1 g, 3.77 mmol) and TMSOTf (0.29 g, 1.32 mmol) were added. Then the mixture was stirred, once the reaction was complete (as indicated by HPLC analysis) it was quenched with water (6 mL, 6 P.) and MeCN (30 mL). The mixture was filtrated and the filtrate cake was washed with MeCN (20 mL) and EtOH (5 mL), then it was dried under vacuum at 40° C. overnight to give the goal product 15 (1.92 g, 97% yield) as a yellow to brown powder with about 82.1% HPLC purity. The reaction mixture was then heated to reflux maintained at that temperature for no less than 5 hours Monitor the reaction by GC was quenched with water (6 mL, 6 P.) and MeCN (30 mL) The mixture was filtrated the filtrate cake was washed with MeCN (20 mL) and EtOH (5 mL) it was dried under vacuum at 40° C. overnight