Potassium Carbonate → Benzoate

Participants

Reaction Conditions

Reaction Steps

Ethyl 2-(4-((1E,4E)-2-amino-4-((3-hydroxypropyl)(propyl)carbamoyl)-3H-benzo[b]azepin-8-yl)phenyl)acetate (40%) was prepared as follows, substituting 4-(2-ethoxy-2-oxoethyl)phenylboronic acid for 4-(ethoxycarbonyl)phenylboronic acid. Ethyl 4-((1E,4E)-2-(tert-butoxycarbonylamino)-4-(3-(tert-butyldimethylsilyloxy)propyl)(propyl)carbamoyl)-3H-benzo[b]azepin-8-yl)benzoate (44%) was prepared as follows, substituting tert-butyl (1E,4E)-8-bromo-4-((3-(tert-butyldimethylsilyloxy)propyl)(propyl)carbamoyl)-3H-benzo[b]azepin-2-ylcarbamate for 1E,4E)-2-amino-8-bromo-N,N-dipropyl-3H-benzo[b]azepine-4-carboxamide and 4-(ethoxycarbonyl)phenylboronic acid for 4-(methoxycarbonyl)phenylboronic acid. (1E,4E)-2-amino-8-bromo-N,N-dipropyl-3H-benzo[b]azepine-4-carboxamide (75.0 mgs, 0.206 mmol), 4-(methoxycarbonyl)phenylboronic acid (55.6 mgs, 0.309 mmol, tetrakis(triphenylphosphine)palladium(0) (23.8 mgs, 0.021 mmol), 2M aqueous potassium carbonate (0.309 ml, 0.618 mmol) were combined in 2 mls of acetonitrile in a microwave reaction vial. This mixture was heated in a microwave to 100° C. for 30 minutes. The mixture was then diluted with EtOAc, washed twice with brine, dried over sodium sulfate, and concentrated under reduced pressure. Preparative thin layer chromatography (2×0.5 mm plates, 7% MeOH/DCM) was then used. Ethyl 4-((1E,4E)-2-(tert-butoxycarbonylamino)-4-((3-(tert-butyldimethylsilyloxy)propyl)(propyl)carbamoyl)-3H-benzo[b]azepin-8-yl)benzoate (0.050 g, 0.075 mmol) was dissolved in 2 mls of dichloromethane and 0.5 ml of TFA. After about one hour, the mixture was concentrated under reduced pressure and the resulting residue was then re-dissolved in dichloromethane and 1 ml of concentrated ammonium hydroxide added and the mixture vigorously stirred for 15 minutes. This mixture was then diluted with water, extracted with dichloromethane (2×), extracts dried over sodium sulfate and concentrated under reduced pressure. Preparative thin layer chromatography (2×0.5 mm plates, 10% MeOH/DCM/0.5% NH4OH) was used. 1H NMR (400 MHz, DMSO-d6) δ 7.60-7.68 (m, 2H), 7.20-7.41 (m, 5H), 6.73-6.85 (m, 3H), 4.42-4.52 (m, 1H), 4.05-4.16 (m, 2H), 3.71 (s, 2H), 3.24-3.52 (m, 6H, partially obscured by water peak), 2.75 (s, 2H), 1.66-1.78 (m, 2H), 1.50-1.65 (m, 2H), 1.15-1.23 (m, 3H), 0.75-0.92 (m, 3H); m/z (APCI-pos) M+1=464.2.

Provenance & Evidence