2-amino-1-(4-bromophenyl)ethanone;hydrochloride

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

Procedure: 2-Amino-1-(4-bromo-phenyl)-ethanone HCl salt (664 mg, 2.65 mmol) was dissolved in DMF (10 mL) and to this solution was added 4-Cyano-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester crude from the previous step, diisopropyl ethylamine (0.93 mL, 5.3 mmol), followed by HATU (1 g, 2.65 mmol). Reaction mixture was stirred at 0° C. for 30 minutes. The reaction mixture was dissolved in ethyl acetate and washed with dilute sodium bicarbonate solution. The organic layer was dried (MgSO4), concentrated and purified by flash column chromatography (silica gel, 20 to 80% ethyl acetate/hexane) to give 2-[2-(4-Bromo-phenyl)-2-oxo-ethylcarbamoyl]-4-cyano-pyrrolidine-1-carboxylic acid tert-butyl ester (1.05 g, yield 91%). LCMS-ESI−: calc'd for C19H22BrN3O4: 435.08. Found: 458.0 (M+Na+). Reaction mixture washed with dilute sodium bicarbonate solution The organic layer was dried (MgSO4) concentrated purified by flash column chromatography (silica gel, 20 to 80% ethyl acetate/hexane)

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

Procedure: 5-Aza-spiro[2.4]heptane-5,6-dicarboxylic acid 5-benzyl ester (361 mg, 1.25 mmol) was dissolved in MeOH (10 mL) and LiOH (1 M in H2O, 5 mL, 5 mmol) was added. After stirring for 15 hours at room temperature, the reaction mixture was poured into 10% HCl and the aqueous phase was extracted 3× with DCM. The combined organics were dried over MgSO4, filtered and concentrated. The residue was treated with 2-Amino-1-(4-bromo-phenyl)-ethanone hydrochloride (344 mg, 1.38 mmol), HATU (525 mg, 1.38 mmol) and DMF (14 mL). The suspension was stirred at 0° C. for 21 minutes before DIPEA (0.72 mL, 4.1 mmol) was added dropwise. Immediately after addition, the reaction mixture was warmed to room temperature. 40 minutes later the mixture was diluted with EtOAc. The organic layer was washed with saturated aqueous NaHCO3 and brine, then dried over MgSO4, filtered and concentrated. The crude residue was purified by silica column chromatography (30% to 50% EtOAc/hexane) to afford 6-[2-(4-Bromo-phenyl)-2-oxo-ethylcarbamoyl]-5-aza-spiro[2.4]heptane-5-carboxylic acid benzyl ester (589 mg, 100%). the aqueous phase was extracted 3× with DCM The combined organics were dried over MgSO4 filtered concentrated was added dropwise Immediately after addition the reaction mixture was warmed to room temperature The organic layer was washed with saturated aqueous NaHCO3 and brine dried over MgSO4 filtered concentrated The crude residue was purified by silica column chromatography (30% to 50% EtOAc/hexane)

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

Procedure: 3-(2-Methoxycarbonylamino-3-methyl-butyryl)-1-phenyl-imidazolidine-4-carboxylic acid methyl ester (51 mg, 0.14 mmol) was dissolved in THF (1.2 mL) and MeOH (0.8 mL). An aqueous solution of LiOH (6.0 mg, 0.14 mmol) was added and stirring at room temperature was continued. After the hydrolysis was complete, the reaction was neutralized with aqueous HCl (1M). The organic solvents were removed in vacuo and the aqueous suspension was frozen and lyophilized. The crude material was used in the next step without further purification. The crude material was dissolved in DMF (1.5 mL) and HATU (54.3 mg, 0.14 mmol) and DIEA (36.9 mg, 0.28 mmol) were added. The reaction was stirred at room temperature for five minutes, after which the amino-(4′ bromo) acetophenone hydrochloride salt (35.7 mg, 0.14 mmol) was added. Stirring at room temperature was continued. After 10 minutes, all volatiles were removed in vacuo and the crude material was purified via silica gel chromatography (eluent: EtOAc/hexanes) to yield the slightly impure product (95 mg): LCMS-ESI+: calc'd for C25H29BrN4O5: 545.4 (M+). Found: 545.2/547.4 (M+H+). The organic solvents were removed in vacuo the aqueous suspension was frozen The crude material was used in the next step without further purification The crude material was dissolved in DMF (1.5 mL) The reaction was stirred at room temperature for five minutes Stirring at room temperature all volatiles were removed in vacuo the crude material was purified via silica gel chromatography (eluent: EtOAc/hexanes)

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

Procedure: 1-Acetyl-3-(2-methoxycarbonylamino-3-methyl-butyryl)-imidazolidine-4-carboxylic acid methyl ester (273 mg, 0.829 mmol) was dissolved in THF (1.8 mL) and MeOH (1.2 mL). An aqueous solution of LiOH (34.8 mg, 0.829 mmol) was added and stirring at room temperature was continued. After the hydrolysis was complete, the reaction was neutralized with aqueous HCl (0.83 mL, 1M). The organic solvents were removed in vacuo and the aqueous suspension was frozen and lyophilized. The crude material was used in the next step without further purification. The crude material was dissolved in DMF (3 mL) and HATU (315 mg, 0.829 mmol) and DIEA (106 mg, 0.829 mmol) were added. The reaction was stirred at room temperature for five minutes, after which the amino-(4′ bromo) acetophenone hydrochloride salt (207 mg, 0.829 mmol) was added. Stirring at room temperature was continued. After 120 minutes, all volatiles were removed in vacuo and the crude material was dissolved in DCM. The organic layer was washed with aqueous HCl (0.5 M), aqueous lithium chloride solution (5%), brine and was dried over sodium sulfate. Filtration and evaporation of solvents yielded crude product which was purified via silica gel chromatography (eluent EtOAc/hexanes) to yield the product (1-{3-Acetyl-5-[2-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-imidazolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (203 mg, 0.397 mmol): LCMS-ESI+: calc'd for C21H27BrN4O6: 511.4 (M+). Found: 511.3/513.2 (M+H+). The organic solvents were removed in vacuo the aqueous suspension was frozen The crude material was used in the next step without further purification The crude material was dissolved in DMF (3 mL) The reaction was stirred at room temperature for five minutes Stirring at room temperature all volatiles were removed in vacuo the crude material was dissolved in DCM The organic layer was washed with aqueous HCl (0.5 M), aqueous lithium chloride solution (5%), brine was dried over sodium sulfate Filtration and evaporation of solvents yielded crude product which was purified via silica gel chromatography (eluent EtOAc/hexanes)

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

Procedure: 3-(2-Methoxycarbonylamino-3-methyl-butyryl)-1-(2,2,2-trifluoro-ethyl)-imidazolidine-4-carboxylic acid methyl ester (95 mg, 0.257 mmol) was dissolved in THF (1.8 mL) and MeOH (0.9 mL). An aqueous solution of LiOH (10.8 mg, 0.208 mmol) was added and stirring at room temperature was continued. After the hydrolysis was complete, the reaction was neutralized with aqueous HCl (1M). The organic solvents were removed in vacuo and the aqueous suspension was frozen and lyophilized. The crude material was used in the next step without further purification. The crude material was dissolved in DMF (1.5 mL) and HATU (97.6 mg, 0.257 mmol) and DIEA (66.3 mg, 0.514 mmol) were added. The reaction was stirred at room temperature for five minutes, after which the amino-(4′ bromo) acetophenone hydrochloride salt (64.2 mg, 0.257 mmol) was added. Stirring at room temperature was continued. After 60 minutes, all volatiles were removed in vacuo and the crude material was purified via silica gel chromatography (eluent: EtOAc/hexanes) to yield the slightly impure product {1-[5-[2-(4-Bromo-phenyl)-2-oxo-ethylcarbamoyl]-3-(2,2,2-trifluoro-ethyl)-imidazolidine-1-carbonyl]-2-methyl-propyl}-carbamic acid methyl ester (148 mg): LCMS-ESI+: calc'd for C21H26BrF3N4O5: 551.3 (M+). Found: 551.2/553.2 (M+). The organic solvents were removed in vacuo the aqueous suspension was frozen The crude material was used in the next step without further purification The crude material was dissolved in DMF (1.5 mL) The reaction was stirred at room temperature for five minutes Stirring at room temperature all volatiles were removed in vacuo the crude material was purified via silica gel chromatography (eluent: EtOAc/hexanes)

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

Procedure: 3-(2-Methoxycarbonylamino-3-methyl-butyryl)-imidazolidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-methyl ester (460 mg, 1.18 mmol) was dissolved in THF (3 mL) and MeOH (2 mL). An aqueous solution of LiOH (49.8 mg, 1.18 mmol) was added and stirring at room temperature was continued. After the hydrolysis was complete, the reaction was neutralized with aqueous HCl (1.18 mL, 1M). The organic solvents were removed in vacuo and the aqueous suspension was frozen and lyophilized. The crude material was used in the next step without further purification. The crude material was dissolved in DMF (4.0 mL) and HATU (448 mg, 1.18 mmol) and DIEA (152 mg, 1.18 mmol) were added. The reaction was stirred at room temperature for five minutes, after which the amino-(4′ bromo) acetophenone hydrochloride salt (295 mg, 1.18 mmol) was added. Stirring at room temperature was continued. After 90 minutes, all volatiles were removed in vacuo and the crude material was purified via silica gel chromatography (eluent: EtOAc/hexanes) to yield the slightly impure product 4-[2-(4-Bromo-phenyl)-2-oxo-ethylcarbamoyl]-3-(2-methoxycarbonylamino-3-methyl-butyryl)-imidazolidine-1-carboxylic acid tert-butyl ester (723 mg): LCMS-ESI+: calc'd for C24H33BrN4O7: 569.4 (M+). Found: 570.4/572.4 (M+H+). The organic solvents were removed in vacuo the aqueous suspension was frozen The crude material was used in the next step without further purification The crude material was dissolved in DMF (4.0 mL) The reaction was stirred at room temperature for five minutes Stirring at room temperature all volatiles were removed in vacuo the crude material was purified via silica gel chromatography (eluent: EtOAc/hexanes)

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

Procedure: 2-Amino-1-(4-bromo-phenyl)-ethanone HCl (5.8 g, 23 mmol) in DMF (75 mL) was treated with 1-tert-butoxycarbonylamino-cyclobutanecarboxylic acid (5.0 g, 23 mmol), HATU (9.7 g, 25 mmol), and DIPEA (12.9 mL, 34 mmol). The mixture was stirred for 18 hours and concentrated. The mixture was diluted with EtOAc (25 mL), and washed with saturated NaHCO3 (3 10 mL), H2O (10 mL), and brine (10 mL). The solution was dried over MgSO4 to afford crude {1-[2-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-cyclobutyl}-carbamic acid tert-butyl ester, which was used without further purification. This material (6.54 g, 16 mmol) in xylenes (40 mL) was treated with ammonium acetate (6.1 g, 80 mmol). The reaction was stirred at 130° C. in a sealed tube for 18 hours. The mixture was concentrated and suspended in dicholormethane (100 mL) and washed with saturated NaHCO3 (50 mL). The solution was dried over MgSO4 to afford crude {1-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-cyclobutyl}-carbamic acid tert-butyl ester, which was used without further purification: MS (ESI) m/z 393 [M+H]+. concentrated The mixture was diluted with EtOAc (25 mL) washed with saturated NaHCO3 (3 10 mL), H2O (10 mL), and brine (10 mL) The solution was dried over MgSO4

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

Procedure: 2-Amino-1-(4-bromo-phenyl)-ethanone HCl (2.5 g, 10 mmol) in DMF (30 mL) was treated with 1-tert-butoxycarbonylamino-cyclopropanecarboxylic acid (1.97 g, 9.8 mmol), HATU (4.02 g, 10.5 mmol), and DIPEA (5.6 mL, 31.1 mmol). The mixture was stirred for 18 hours and concentrated. The mixture was diluted with EtOAc (25 mL), and washed with saturated NaHCO3 (3 10 mL), H2O (10 mL), and brine (10 mL). The solution was dried over MgSO4 and subjected to a 80 g SiO2 COMBIFLASH column (0-100% EtOAc-hexanes gradient) to afford {1-[2-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-cyclopropyl}-carbamic acid tert-butyl ester (3.49 g, 90%). This material (3.49 g, 8.8 mmol) in xylenes (20 mL) was treated with ammonium acetate (3.4 g, 44 mmol). The reaction was stirred at 130° C. in a sealed tube for 18 hours. The mixture was concentrated and suspended in dicholormethane (100 mL) and washed with saturated NaHCO3 (50 mL). The solution was dried over MgSO4 to afford crude {1-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-cyclopropyl}-carbamic acid tert-butyl ester, which was used without further purification: MS (ESI) m/z 379 [M+H]+. concentrated The mixture was diluted with EtOAc (25 mL) washed with saturated NaHCO3 (3 10 mL), H2O (10 mL), and brine (10 mL) The solution was dried over MgSO4

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

Procedure: 2,6-Dioxo-morpholine-4-carboxylic acid tert-butyl ester (2.5 g, 11.6 mmol) was added to a solution of 2-amino-1-(4-bromo-phenyl)-ethanone hydrochloride (3.05 g, 12.2 mmol) and 4-methylmorpholine (1.92 mL, 17.4 mmol) in dimethylformamide (15 mL). After 30 min the solvent was removed under reduced pressure. The residue was taken up in ethyl acetate (100 mL) and washed with water (50 mL), aqueous hydrogen chloride (0.5 N, 2×50 mL), and saturated sodium bicarbonate (2×50 mL). The basic extracts were neutralized and extracted with ethyl acetate (2×75 mL). The combined organic phases from the second extraction were dried over sodium sulfate, and filtered. The solvent was removed under reduced pressure to provide ({[2-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-methyl}-tert-butoxycarbonyl-amino)-acetic acid (4 g, 9.3 mmol, 80%). C17H21BrN2O6 calculated 428.0 observed [M+1]+431.1; rt=2.36 min. After 30 min the solvent was removed under reduced pressure washed with water (50 mL), aqueous hydrogen chloride (0.5 N, 2×50 mL), and saturated sodium bicarbonate (2×50 mL) extracted with ethyl acetate (2×75 mL) The combined organic phases from the second extraction were dried over sodium sulfate filtered The solvent was removed under reduced pressure

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

Procedure: A solution of 4-oxo-hexahydro-pyrrolo[1,2-a]pyrazine-2,6-dicarboxylic acid 2-methyl ester (81 mg, 0.33 mmol), HATU (152 mg, 0.40 mmol), and 4-methyl morpholine (146 μL, 1.33 mmol) in dimethylformamide (4 mL) was stirred at ambient temperature for 5 minutes. 2-Amino-1-(4-bromo-phenyl)-ethanone hydrochloride (91 mg, 0.37 mmol) was added to the reaction mixture. After 1 hour the solvent was removed under reduced pressure and the resulting residue was taken up in ethyl acetate (10 mL). The resulting mixture contained a solid and was filtered. The solvent was removed under reduced pressure from the filtrate. The resulting residue was subjected to flash chromatography with eluent of (10% methanol in ethyl acetate) and hexane. The product-containing fractions were combined and the solvent was removed under reduced pressure to provide 6-[2-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-4-oxo-hexahydro-pyrrolo[1,2-a]pyrazine-2-carboxylic acid methyl ester (110 mg, 0.25 mmol, 75%). C18H20BrN3O5 calculated 437.1 observed [M+1]+ 438.1; rt=1.82 min. After 1 hour the solvent was removed under reduced pressure was filtered The solvent was removed under reduced pressure from the filtrate the solvent was removed under reduced pressure

Conditions: temp:95.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-amino-4-bromoacetophenone hydrochloride (4.0 g, 16.0 mmol), sodium acetate (6.1 g, 90.0 mmol), acetic acid (4.6 mL, 80.0 mmol) and ethyl 2-imino-2-(methylthio)acetate (7.7 g, 32.0 mmol) in dioxane (40 mL) was stirred at 95° C. overnight. The reaction mixture was carefully neutralized with saturated NaHCO3 solution and extracted with ethyl acetate. The organic solution was dried over sodium sulfate and concentrated. Purification by silica gel column chromatography (ethyl acetate:hexanes 1:1) afforded ethyl 4-(4-bromophenyl)-1H-imidazole-2-carboxylate (3.53 g, 75.0%). MS (EI) for C12H11BrN2O2: 296 (MH+). extracted with ethyl acetate The organic solution was dried over sodium sulfate concentrated Purification by silica gel column chromatography (ethyl acetate:hexanes 1:1)

Conditions: temp:95.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-amino-4-bromoacetophenone hydrochloride (4.0 g, 16.0 mmol), sodium acetate (6.1 g, 90.0 mmol), acetic acid (4.6 mL, 80.0 mmol) and ethyl 2-imino-2-(methylthio)acetate (7.7 g, 32.0 mmol) in dioxane (40 mL) was stirred at 95° C. overnight. The reaction mixture was carefully neutralized with saturated NaHCO3 solution and extracted with ethyl acetate. The organic solution was dried over sodium sulfate and concentrated. Purification by silica gel column chromatography (ethyl acetate:hexanes 1:1) afforded ethyl 4-(4-bromophenyl)-1H-imidazole-2-carboxylate (3.53 g, 75.0%). MS (EI) for C12H11BrN2O2: 296 (MH+). extracted with ethyl acetate The organic solution was dried over sodium sulfate concentrated Purification by silica gel column chromatography (ethyl acetate:hexanes 1:1)