Triethylamine → Pyrrolidine-1,2-dicarboxylic acid 2-[2-(6-bromo-naphthalen-2-yl)-2-oxo-ethyl]ester 1-tert-butyl ester

HRID 2392366Notes

Reaction equation

HRID 2392366 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12](=[O:25])[CH2:13][O:14][C:15]([CH:17]1[CH2:21][CH2:20][CH2:19][N:18]1[C:22]([OH:24])=[O:23])=[O:16])[CH:6]=[CH:5]2.[C:26](OC(N1CCCC1C(O)=O)=O)([CH3:29])([CH3:28])[CH3:27].C(N(CC)CC)C.BrCC(C1C=CC2C(=CC=C(Br)C=2)C=1)=O>C(#N)C>[C:26]([O:23][C:22]([N:18]1[CH2:19][CH2:20][CH2:21][CH:17]1[C:15]([O:14][CH2:13][C:12]([C:7]1[CH:6]=[CH:5][C:4]2[C:9](=[CH:10][CH:11]=[C:2]([Br:1])[CH:3]=2)[CH:8]=1)=[O:25])=[O:16])=[O:24])([CH3:29])([CH3:28])[CH3:27]

Participants

6

Reactant 4

HCID 8471TriethylamineHCID 2684721-[(Tert-butoxy)carbonyl]pyrrolidine-2-carboxylic acidHCID 126988982-Bromo-1-(6-bromonaphthalen-2-yl)ethanoneHCID 66788455HCID 66788455, compound

Product 1

HCID 66620206Pyrrolidine-1,2-dicarboxylic acid 2-[2-(6-bromo-naphthalen-2-yl)-2-oxo-ethyl]ester 1-tert-butyl esterYield 84%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent2×

Procedure

6-Bromonaphthalene-2-carboxylic acid (25.1 g) was suspended in thionyl chloride (200 mL), stirred at 60° C. for 16 hours and evaporated under vacuum. Solid was dissolved in dichloromethane (50 mL) and evaporated under vacuum, giving 6-bromonaphthalene-2-carbonyl chloride (27.0 g, crude) as a white solid. 1-(6-Bromo-naphthalen-2-yl)-2-diazo-ethanone: 6-Bromonaphthalene-2-carbonyl chloride (27.0 g, crude) was dissolved in dichloromethane (330 mL) and cooled to 0° C. TMS diazomethane solution (100 mL, 2 M in DCM) was added, and ice bath was removed. Reaction mixture was stirred for 16 hours and evaporated under vacuum, giving 1-(6-bromonaphthalen-2-yl)-2-diazoethanone (34.7 g, crude) as an orange solid. 2-Bromo-1-(6-bromo-naphthalen-2-yl)-ethanone: 1-(6-Bromonaphthalen-2-yl)-2-diazoethanone (34.7 g) were dissolved in ethyl acetate (500 mL), and hydrobromic acid solution (21.1 mL, 5.7 M in acetic acid) was added at 0° C. Reaction mixture was stirred 3 hours, NaHCO3 solution (200 mL) was added, and mixture was stirred 10 minutes. Ethyl acetate solution was extracted twice with NaHCO3 solution (50 mL), once with brine (50 mL), and evaporated under vacuum, giving 2-bromo-1-(6-bromonaphthalen-2-yl)-ethanone (33.0 g, crude) as a tan solid. Pyrrolidine-1,2-dicarboxylic acid 2-[2-(6-bromo-naphthalen-2-yl)-2-oxo-ethyl]ester Wert-butyl ester: Pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester (24.0 g) was dissolved in acetonitrile (330 mL), and triethylamine (15.6 mL) was added. A solution of 2-bromo-1-(6-bromonaphthalen-2-yl)-ethanone (33.0 g) in acetonitrile (170 mL) were added. Reaction mixture was stirred over 3 days and evaporated under vacuum. Oil was dissolved in dichloromethane (100 mL), extracted with water (50 mL) and with NaHCO3 solution (50 mL), and evaporated under vacuum to a concentrated liquid. Solution was purified by chromatography (0-30% ethyl acetate:hexane) and evaporated under vacuum, giving pyrrolidine-1,2-dicarboxylic acid 2-[2-(6-bromo-naphthalen-2-yl)-2-oxo-ethyl]ester 1-tert-butyl ester (39.2 g, 84%) as a tan solid. 2-[5-(6-Bromo-naphthalen-2-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester: Pyrrolidine-1,2-dicarboxylic acid 242-(6-bromonaphthalen-2-yl)-2-oxo-ethyl]ester 1-tert-butyl ester (39.0 g) and ammonium acetate (40.1 g) were suspended in xylenes (420 mL). The reaction mixture was stirred at 140° C. for 15 hours and evaporated under vacuum. Solid was dissolved in dichloromethane (300 mL), extracted twice with water (50 mL) and once with brine (50 mL), and evaporated under vacuum, giving 2-[5-(6-bromonaphthalen-2-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (30.3 g, 81%) as an off-white solid. 5-(6-Bromo-naphthalen-2-yl)-2-pyrrolidin-2-yl-1H-imidazole: 2-[5-(6-Bromonaphthalen-2-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (5.03 g) was dissolved in dichloromethane (75 mL), and trifluoroacetic acid (25 mL) was added. The reaction mixture was stirred at ambient temperature for 5 hours and evaporated under vacuum. Solid was dissolved in dichloromethane (50 mL) and extracted with saturated NaHCO3 solution (50 mL). Solid was collected by vacuum filtration, washed with dichloromethane, and dried under vacuum, giving 5-(6-Bromo-naphthalen-2-yl)-2-pyrrolidin-2-yl-1H-imidazole (98%) as an off-white solid. (1-{2-[5-(6-Bromonaphthalen-2-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester: 5-(6-Bromo-naphthalen-2-yl)-2-pyrrolidin-2-yl-1H-imidazole (3.80 g), 2-methoxycarbonylamino-3-methyl-butyric acid (2.21 g), and HATU (5.06 g) were dissolved in anhydrous DMF (75 mL), and N-methylmorpholine (2.68 mL) was added. The reaction mixture was stirred at ambient temperature for 16 hours and evaporated under vacuum. The oil was dissolved in dichloromethane, purified by chromatography (0-100% ethyl acetate:hexanes), and evaporated under vacuum, giving (1-{2-[5-(6-bromo-naphthalen-2-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (0.814 g, 72%) as an off-white solid. [2-Methyl-1-(2-{5-[6-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-naphthalen-2-yl]-1H-imidazol-2-yl}-pyrrolidine-1-carbonyl)-propyl]-carbamic acid methyl ester: (1-{2-[5-(6-Bromonaphthalen-2-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (3.02 g), bis-(pinocolato)diborane (3.18 g), and potassium acetate (1.52 g) were dissolved in 1,4-dioxane (40 mL), and solution was degassed with nitrogen. Pd(PPh3)4 (0.285 g) was added, and the reaction mixture was stirred at 80° C. for 20 hours and evaporated under vacuum. Solid was dissolved in dichloromethane (50 mL), extracted with saturated NaHCO3 solution (50 mL), and evaporated under vacuum. The oil was dissolved in dichloromethane, purified by chromatography (0-10% isopropanol:dichloromethane), and evaporated under vacuum, giving [2-Methyl-1-(2-{5-[6-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-naphthalen-2-yl]-1H-imidazol-2-yl}-pyrrolidine-1-carbonyl)-propyl]-carbamic acid methyl ester (3.65 g, crude) as a yellow solid. (1-{2-[5-(6′-(2-[1-(2-Methoxycarbonylamino-3-methyl-butyryl)-pyrrolidin-2-yl]-3H-imidazol-4-yl}-[2,2′]binaphthalenyl-6-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester: (1-{2-[5-(6-Bromonaphthalen-2-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (0.174 g), [2-Methyl-1-(2-{5-[6-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-naphthalen-2-yl]-1H-imidazol-2-yl}-pyrrolidine-1-carbonyl)-propyl]-carbamic acid methyl ester (0.202 g), and NaHCO3 (0.108 g) were dissolved in a mixture of 1,2-dimethoxyethane (6 mL) and water (2 mL). The solution was degassed with nitrogen, and Pd(PPh3)4 (0.0176 g) was added. The reaction mixture was stirred at 85° C. for 16 hours and evaporated under vacuum. Solid was dissolved in ethyl acetate (10 mL) and extracted twice with water (10 mL) and once with brine (10 mL). Solution was evaporated, dissolved in DMF, purified by reverse phase HPLC (5-70% acetonitrile:water), and lyophilized, giving (1-{2-[5-(6′-{2-[1-(2-Methoxycarbonylamino-3-methyl-butyryl)-pyrrolidin-2-yl]-3H-imidazol-4-yl}-[2,2′]binaphthalenyl-6-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (0.050 g, 16%) as a white solid: 1H-NMR: 300 MHz, (MeOH-d4) δ: 8.3 (m, 4H), 8.1 (m, 6H), 8.0 (s, 2H), 7.8 (d, J=9.4, 2H), 5.3 (m, 2H), 4.3 (d, J=9.0, 2H), 4.1 (m, 2H), 3.9 (m, 2H), 3.7 (s, 6H), 2.6 (m, 2H), 2.2 (m, 6H), 0.9 (m, 12H); MS (ESI) m/z 839 [M+H]+.

Workup

  1. customReaction mixture
  2. customevaporated under vacuum
  3. dissolutionOil was dissolved in dichloromethane (100 mL)
  4. extractionextracted with water (50 mL) and with NaHCO3 solution (50 mL)
  5. customevaporated under vacuum to a concentrated liquid
  6. customSolution was purified by chromatography (0-30% ethyl acetate:hexane)
  7. customevaporated under vacuum

Sources & evidence

ORD record
ord-dc02dfdf58a741c4919990a78a02f977
Source dataset
uspto-grants-2012_09
Patent number
US08273341B2

Reaction notes

Loading…