1-Chloro-4-(chloromethyl)benzene → HCID 67269259, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of LDA (1.80 M in THF, 20 mmol) in THF (100 mL) at −78° C., was added a solution of 3-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester (10 mmol) in THF (10 mL) dropwise. After 20 min, a solution of 4-chlorobenzyl chloride (15 mmol) in THF (10 mL) was added. Then the mixture was warmed to 25° C. and stirred for 16 h. Satd. aq. NaHCO3 (100 mL) was added, and the organic layer was separated and concentrated to give 3-(4-chloro-benzyl)-4-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester. This residue (⅛ portion, approx. 1.25 mmol) was diluted with EtOH (10 mL) and treated with benzyl hydrazine hydrogen chloride (1.5 mmol) and K2CO3 (5 mmol). The mixture was stirred at 25° C. for 16 h. Concentration and purification by flash chromatography (EtOAc/CH2Cl2) provided 2-benzyl-3-(4-chloro-phenyl)-2,6-dihydro-4H-pyrrolo[3,4-c]pyrazole-5-carboxylic acid tert-butyl ester. A solution of the ester and TFA (2 mL) in CH2Cl2 (10 mL) was stirred at 25° C. for 4 h. Concentration and purification by flash chromatography (2 M NH3 in MeOH/CH2Cl2) provided the desired compound (10 mg). MS (ESI): exact mass calculated for C18H16ClN3, 309.10; found, m/z 310.4 [M+H]+. 1H NMR (500 MHz, CDCl3): 7.37-7.21 (m, 7H), 7.08-7.05 (m, 2H), 5.29 (s, 2H), 4.09 (s, 2H), 4.04 (s, 2H).

Provenance & Evidence