4-(4-Aminobenzyl)piperazine-1-carboxylic acid tert-butyl ester

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-chloro-5-methyl-pyrimidin-4-ylamine (0.35 g, 2.4 mmol) and 4-(4-amino-benzyl)-piperazine-1-carboxylic acid tert-butyl ester (0.80 g, 2.8 mmol) in acetic acid (20 mL) was heated at 70° C. for 1 d. After cooling to room temperature, the mixture was concentrated. The residue was taken in water (30 mL) and neutralized with 10% NaOH solution until pH˜10. The resulting aqueous layer was extracted with EtOAc (2×30 mL) and the combined organic layers washed with brine, dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated and the title compound used in the next step without purification. MS (ES+): m/z 399 (M+H)+. After cooling to room temperature the mixture was concentrated The resulting aqueous layer was extracted with EtOAc (2×30 mL) the combined organic layers washed with brine dried over anhydrous Na2SO4 filtered The filtrate was concentrated the title compound used in the next step without purification

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-chloro-5-methyl-pyrimidin-4-ylamine (0.35 g, 2.4 mmol) and 4-(4-amino-benzyl)-piperazine-1-carboxylic acid tert-butyl ester (0.80 g, 2.8 mmol) in acetic acid (20 mL) was heated at 70° C. for 1 d. After cooling to room temperature, the mixture was concentrated. The residue was taken in water (30 mL) and neutralized with 10% NaOH solution until pH˜10. The resulting aqueous layer was extracted with EtOAc (2×30 mL) and the combined organic layers washed with brine, dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated and the title compound used in the next step without purification. MS (ES+): m/z 399 (M+H)+. After cooling to room temperature the mixture was concentrated The resulting aqueous layer was extracted with EtOAc (2×30 mL) the combined organic layers washed with brine dried over anhydrous Na2SO4 filtered The filtrate was concentrated the title compound used in the next step without purification

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethyl 2,4-dichloro-6-methylpyrimidine-5-carboxylate (0.5 g, 2.1 mmol) and tert-butyl 4-(4-aminobenzyl)piperazine-1-carboxylate (0.6 g, 2.06 mmol) were dissolved in NMP and stirred at 0° C. for 2 hour. The reaction mixture was poured onto water and extracted with EtOAc. The organic layer was washed with water, dried over Na2SO4 and evaporated under vacuum to get the desired compound (0.62 g). 1H NMR (400 MHz, CDCl3): δ 10.58 (s, 1H), 7.58 (d, J=6.4 Hz, 2H), 7.31 (d, J=6.4 Hz, 2H), 4.45 (q, J=6.8 Hz, 2H), 3.56 (s, 2H), 3.41 (m, 4H), 2.69 (s, 3H), 2.47 (m, 4H), 1.45 (s, 9H), 1.43 (t, J=6.8 Hz, 3H); MS m/z 490.0 (M+1). The reaction mixture was poured onto water extracted with EtOAc The organic layer was washed with water dried over Na2SO4 evaporated under vacuum

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethyl 2,4-dichloro-6-methylpyrimidine-5-carboxylate (0.5 g, 2.1 mmol) and tert-butyl 4-(4-aminobenzyl)piperazine-1-carboxylate (0.6 g, 2.06 mmol) were dissolved in NMP and stirred at 0° C. for 2 hour. The reaction mixture was poured onto water and extracted with EtOAc. The organic layer was washed with water, dried over Na2SO4 and evaporated under vacuum to get the desired compound (0.62 g). 1H NMR (400 MHz, CDCl3): δ 10.58 (s, 1H), 7.58 (d, J=6.4 Hz, 2H), 7.31 (d, J=6.4 Hz, 2H), 4.45 (q, J=6.8 Hz, 2H), 3.56 (s, 2H), 3.41 (m, 4H), 2.69 (s, 3H), 2.47 (m, 4H), 1.45 (s, 9H), 1.43 (t, J=6.8 Hz, 3H); MS m/z 490.0 (M+1). The reaction mixture was poured onto water extracted with EtOAc The organic layer was washed with water dried over Na2SO4 evaporated under vacuum

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

Procedure: tert-Butyl 4-(4-aminobenzyl)piperazine-1-carboxylate (G49) can be prepared by the nucleophilic displacement of commercially available 1-(bromomethyl)-4-nitrobenzene (G47) with tert-butyl piperazine-1-carboxylate (G7) to give tert-butyl 4-(4-nitrobenzyl)piperazine-1-carboxylate (G48). Subsequent reduction with hydrogen in the presence of a catalyst, for example 10% palladium on charcoal, gives tert-butyl 4-(4-aminobenzyl)piperazine-1-carboxylate (G49).

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

Procedure: 4-(4-Nitro-benzyl)-piperazin-1-yl carboxylic acid tert-butyl ester (769 mg, 2.4 mmol) and tin chloride dihydrate (2.70 g, 12 mmol) are suspended in ethyl acetate (20 mL) and stirred at room temperature overnight. Then, saturated aqueous solution of sodium bicarbonate (20 mL) is added and vigorously stirred for 1 hour. Solids are removed by filtration and the organic layer of the filtrate is separated and washed with water (20 mL). The organic phase is dried over anhydrous magnesium sulfate and concentrated to give a white solid (620 mg, 89% yield, ES+(m/z) 293 [M+H]). vigorously stirred for 1 hour Solids are removed by filtration the organic layer of the filtrate is separated washed with water (20 mL) The organic phase is dried over anhydrous magnesium sulfate concentrated to give a white solid (620 mg, 89% yield, ES+(m/z) 293 [M+H])

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-chloro-5-methyl-pyrimidin-4-ylamine (0.35 g, 2.4 mmol) and 4-(4-amino-benzyl)-piperazine-1-carboxylic acid tert-butyl ester (0.80 g, 2.8 mmol) in acetic acid (20 mL) was heated at 70° C. for 1 d. After cooling to room temperature, the mixture was concentrated. The residue was taken in water (30 mL) and neutralized with 10% NaOH solution until pH ˜10. The resulting aqueous layer was extracted with EtOAc (2×30 mL) and the combined organic layers washed with brine, dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated and the title compound used in the next step without purification. MS (ES+): m/z 399 (M+H)+. After cooling to room temperature the mixture was concentrated The resulting aqueous layer was extracted with EtOAc (2×30 mL) the combined organic layers washed with brine dried over anhydrous Na2SO4 filtered The filtrate was concentrated the title compound used in the next step without purification

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: tert-Butyl 4-(4-aminobenzyl)piperazine-1-carboxylate (G49) can be prepared by the nucleophilic displacement of commercially available 1-(bromomethyl)-4-nitrobenzene (G47) with tert-butyl piperazine-1-carboxylate (G7) to give tert-butyl 4-(4-nitrobenzyl)piperazine-1-carboxylate (G48). Subsequent reduction with hydrogen in the presence of a catalyst, for example 10% palladium on charcoal, gives tert-butyl 4-(4-aminobenzyl)piperazine-1-carboxylate (G49).