methyl 4-amino-3,5-dibromobenzoate

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

Procedure: Methyl 3,5-dibromo-4-chlorobenzoate: CuCl2 (2.82 g, 21.0 mmol) in MeCN (30 mL) was stirred at 80° C. for 30 min. To this mixture tert-butylnitrite (2.7 mL, 23 mmol) was then added dropwise at same temperature and the mixture was stirred for another 10 min. Methyl 4-amino-3,5-dibromobenzoate (5.0 g, 16 mmol) in MeCN (30 mL) was added dropwise to the reaction mixture and then stirred at 80° C. for 30 min. The reaction mixture was brought to ambient temperature and an aqueous ammonia solution (20 mL) was added to the reaction mixture and extracted with petroleum ether. The organic layer was washed with brine followed by water, dried (Na2SO4), filtered and concentrated to afford the title compound as an off white solid (4.5 g, 84%). 1H NMR (300 MHz, DMSO-d6) δ 8.21 (s, 2H), 3.94 (s, 3H); ESIMS m/z 326 ([M]+); IR (thin film) 1732, 746 cm−1. stirred at 80° C. for 30 min was brought to ambient temperature extracted with petroleum ether The organic layer was washed with brine dried (Na2SO4) filtered concentrated

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

Procedure: Methyl 3,5-dibromo-4-chlorobenzoate: CuCl2 (2.82 g, 21.0 mmol) in MeCN (30 mL) was stirred at 80° C. for 30 min. To this mixture tert-butylnitrite (2.7 mL, 23 mmol) was then added dropwise at same temperature and the mixture was stirred for another 10 min. Methyl 4-amino-3,5-dibromobenzoate (5.0 g, 16 mmol) in MeCN (30 mL) was added dropwise to the reaction mixture and then stirred at 80° C. for 30 min. The reaction mixture was brought to ambient temperature and an aqueous ammonia solution (20 mL) was added to the reaction mixture and extracted with petroleum ether. The organic layer was washed with brine followed by water, dried (Na2SO4), filtered and concentrated to afford the title compound as an off white solid (4.5 g, 84%). 1H NMR (300 MHz, DMSO-d6) δ 8.21 (s, 2H), 3.94 (s, 3H); ESIMS m/z 326 ([M]+); IR (thin film) 1732, 746 cm−1. stirred at 80° C. for 30 min was brought to ambient temperature extracted with petroleum ether The organic layer was washed with brine dried (Na2SO4) filtered concentrated

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: conc. H2SO4 (1.35 mL, 25.48 mmol) was added dropwise to a stirred solution of 4-amino-3,5-dibromobenzoic acid (5.0 g, 16.99 mmol) in MeOH (50 mL) at ambient temperature and the reaction mixture was then stirred at 80° C. for 8 h. The reaction mixture was brought to ambient temperature, volatiles were evaporated and ice cold water was added to the residue and which was then extracted with EtOAc. The organic layer was washed with an aqueous NaHCO3 solution followed by brine and water. The solution was then dried (Na2SO4), filtered and concentrated to afford the title compound as an off white solid (5.0 g, 95%): 1H NMR (300 MHz, DMSO-d6) δ 7.91 (s, 2H), 6.20 (bs, 2H), 3.78 (s, 3H); ESIMS m/z 307.0 ([M]+); IR (thin film) 3312, 2953, 1726, 595 cm−1. was brought to ambient temperature volatiles were evaporated ice cold water was added to the residue and which was then extracted with EtOAc The organic layer was washed with an aqueous NaHCO3 solution The solution was then dried (Na2SO4) filtered concentrated

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: conc. H2SO4 (1.35 mL, 25.48 mmol) was added dropwise to a stirred solution of 4-amino-3,5-dibromobenzoic acid (5.0 g, 16.99 mmol) in MeOH (50 mL) at ambient temperature and the reaction mixture was then stirred at 80° C. for 8 h. The reaction mixture was allowed to cool to ambient temperature, volatiles were evaporated and ice-water was added to the residue and extracted with EtOAc. The organic layer was washed with aqueous NaHCO3 solution followed by brine and water, dried (Na2SO4), filtered and concentrated to afford the title compound as an off white solid (5.0 g, 95%): 1H NMR (300 MHz, DMSO-d6) δ 7.91 (s, 2H), 6.20 (bs, 2H), 3.78 (s, 3H); ESIMS m/z 307.0 ([M]+); IR (thin film) 3312, 2953, 1726, 595 cm−1. to cool to ambient temperature volatiles were evaporated ice-water was added to the residue extracted with EtOAc The organic layer was washed with aqueous NaHCO3 solution dried (Na2SO4) filtered concentrated

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

Procedure: Methyl 3,5-dibromo-4-chlorobenzoate: CuCl2 (2.82 g, 21.0 mmol) in MeCN (30 mL) was stirred at 80° C. for 30 min. To this mixture tert-butylnitrite (2.7 mL, 23 mmol) was then added dropwise at same temperature and the mixture was stirred for another 10 min. Methyl 4-amino-3,5-dibromobenzoate (5.0 g, 16 mmol) in MeCN (30 mL) was added dropwise to the reaction mixture and then stirred at 80° C. for 30 min. The reaction mixture was brought to ambient temperature and an aqueous ammonia solution (20 mL) was added to the reaction mixture and extracted with petroleum ether. The organic layer was washed with brine followed by water, dried (Na2SO4), filtered and concentrated to afford the title compound as an off white solid (4.5 g, 84%). 1H NMR (300 MHz, DMSO-d6) δ 8.21 (s, 2H), 3.94 (s, 3H); ESIMS m/z 326 ([M]+); IR (thin film) 1732, 746 cm−1. stirred at 80° C. for 30 min was brought to ambient temperature extracted with petroleum ether The organic layer was washed with brine dried (Na2SO4) filtered concentrated