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To a mixture of malononitrile (2.64 g, 40 mmol) in 95% Ethanol (50 mL) was added 2,3-dichlorobenzaldehyde (7.00 g, 40.0 mmol). The reaction was stirred at rt for 18 h. EtOH (20 mL) was added and the mixture was stirred at rt for 20 min and cooled to 0° C. in an ice bath. Sodium borohydride (0.424 g, 11.20 mmol) was introduced to the vigorously stirred mixture and the reduction was complete in about 10 min. To the reaction mixture was added water (40 mL). 1N HCl was added in to quench the excess hydride. More water was added in until precipitation was complete. Filtration gave [(2,3-dichlorophenyl)methyl]propanedinitrile (7.86 g, 87%). To a solution of [(2,3-dichlorophenyl)methyl]propanedinitrile (7.86 g, 34.9 mmol) in Ethanol (80 mL) was added hydrazine hydrate (2.57 mL, 52.4 mmol). The mixture is heated at reflux temperature for 8 h. The reaction mixture was concentrated. The crude material was purified on a silica column (MeOH/DCM: 0˜10%) to give the product (4.2 g, 47%). 1H NMR (400 MHz, METHANOL-d4) δ ppm 3.77 (s, 2H) 7.09 (m, 1H) 7.19 (t, J=7.96 Hz, 1H) 7.38 (m, 1H); LC/MS: MS (ES+) m/e 257.0 [M+H]+.

1. temperatureThe mixture is heated
2. temperatureat reflux temperature for 8 h
3. concentrationThe reaction mixture was concentrated
4. customThe crude material was purified on a silica column (MeOH/DCM: 0˜10%)