1,2-Dichloro-4-nitrobenzene → Dimethyl 2-(2-chloro-4-nitrophenyl)malonate

NaH (288 mmol) was suspended in DMF (370 mL) at 0° C. under an atmosphere of nitrogen. Dimethyl malonate (261 mmol) in DMF (30 mL) was added dropwise over a period of 20 min. at 0° C. and stirring was continued at 0° C. for 30 min. Then 1,2-dichloro-4-nitrobenzene (130 mmol) in DMF (35 mL) was added dropwise at 0° C. over a period of 20 min. The mixture was stirred at 70° C. for 15 h. The reaction mixture was cooled to room temperature and quenched with NH4Cl. The solution was successively washed with EtOAc (1×100 mL, 1×250 mL) and water (2×150 mL). To facilitate separation of the layers, sat. aq. NaCl (20 mL) was added. The organic layer was separated and washed with sat. aq. NaCl (2×100 mL). The aqueous layer was backextracted with EtOAc (2×50 mL). The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure. The crude material was recrystallized from EtOH to give dimethyl 2-(2-chloro-4-nitrophenyl)malonate as a solid (74%).

1. stirringThe mixture was stirred at 70° C. for 15 h
2. customquenched with NH4Cl
3. washThe solution was successively washed with EtOAc (1×100 mL, 1×250 mL) and water (2×150 mL)
4. customseparation of the layers, sat. aq. NaCl (20 mL)
5. additionwas added
6. customThe organic layer was separated
7. washwashed with sat. aq. NaCl (2×100 mL)
8. dry with materialThe organic layer was dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customThe crude material was recrystallized from EtOH

ORD record

ord-b150edc1ed3e47df8a8e0a1a8d6a56a1

Source dataset

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08232283B2