Methyl 3-isocyanatobenzoate → 3-[3-(2,2-Diethoxyethyl)-3-(4-isopropylphenyl)ureido]benzoic acid methyl ester

HRID 2194824Notes

Reaction equation

HRID 2194824 reaction equation
[CH:1]([C:4]1[CH:9]=[CH:8][C:7]([NH:10][CH2:11][CH:12]([O:16][CH2:17][CH3:18])[O:13][CH2:14][CH3:15])=[CH:6][CH:5]=1)([CH3:3])[CH3:2].[C:19]([C:23]1[CH:24]=[C:25]([N:29]=[C:30]=[O:31])[CH:26]=[CH:27][CH:28]=1)([O:21][CH3:22])=[O:20]>ClCCl>[CH:1]([C:4]1[CH:5]=[CH:6][C:7]([N:10]2[CH:11]=[CH:12][N:29]([C:25]3[CH:24]=[C:23]([CH:28]=[CH:27][CH:26]=3)[C:19]([OH:21])=[O:20])[C:30]2=[O:31])=[CH:8][CH:9]=1)([CH3:2])[CH3:3].[CH3:22][O:21][C:19](=[O:20])[C:23]1[CH:28]=[CH:27][CH:26]=[C:25]([NH:29][C:30]([N:10]([CH2:11][CH:12]([O:13][CH2:14][CH3:15])[O:16][CH2:17][CH3:18])[C:7]2[CH:8]=[CH:9][C:4]([CH:1]([CH3:2])[CH3:3])=[CH:5][CH:6]=2)=[O:31])[CH:24]=1

Participants

5

Procedure

A solution of N-(4-isopropylphenyl)-2,2-diethoxyethylamine (0.50 g, 2.0 mmol) prepared above and 3-carbomethoxyphenyl isocyanate (0.36 g, 2.05 mmol) in dry dichloromethane (10 mL) was stirred at room temperature overnight. The solution was then chromatographed (silica gel, hexanes:ethyl acetate, 8:2) to give the pure urea, 3-[3-(2,2-diethoxyethyl)-3-(4-isopropylphenyl)ureido]benzoic acid methyl ester as a colorless oil (0.73 g, 85.3%). MS (ES−) m/z: 427. This was then stirred with HCl (0.5 M, 50 mL) at 80° C. for 4 h. After cooling to room temperature, the white precipitate formed was collected and purified by chromatography (silica gel, dichloromethane:ethyl acetate, 9:1) to give pure methyl 3-[3-(4-isopropylphenyl)-2-oxo-2,3-dihydroimidazol-1-yl]benzoate as white solid [0.42 g, 73.7%, MS (ES+) m/z: 337]. The solid was then treated with boron tribromide in dichloromethane (1.0 M, 4.0 mL) at room temperature overnight. The volatiles were removed in vacuum and the residue was suspended in water and stirred for 30 min. The solid was collected by filtration and washed with water to furnish 3-[3-(4-isopropylphenyl)-2-oxo-2,3-dihydroimidazol-1-yl]benzoic acid (0.40 g, 100%). m.p. 283-285° C. 1H NMR (CDCl3, 300 MHz) δ (ppm) 1.24 (d, 6H), 2.84-3.00 (m, 1H), 6.69 (d, 1H), 6.74 (d, 1H), 7.26 (d, 2H), 7.45-7.54 (m, 3H), 7.91 (d, 1H), 8.02 (d, 1H), 8.12 (s, 1H). MS (ES−) m/z: 321.

Workup

  1. customThe solution was then chromatographed (silica gel, hexanes:ethyl acetate, 8:2)

Sources & evidence

ORD record
ord-1e9d1a8365ba4549bb5a6643109fe6c8
Source dataset
uspto-grants-2012_12
Patent number
US08334313B2

Reaction notes

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