Dicyclohexylcarbodiimide → (2R)-2-hydroxy-3-(phenylmethoxy)propyl (2S)-2-(6-methoxy(2-naphthyl))propanoate
Reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[CH:9]=[C:8]([C@H:13]([CH3:17])[C:14]([OH:16])=[O:15])[CH:7]=[CH:6]2.[CH2:18]([O:25][CH2:26][C@H:27]([OH:30])[CH2:28]O)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.C1(N=C=NC2CCCCC2)CCCCC1>C(Cl)Cl>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[CH:9]=[C:8]([C@H:13]([CH3:17])[C:14]([O:16][CH2:28][C@H:27]([OH:30])[CH2:26][O:25][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:15])[CH:7]=[CH:6]2Participants
Procedure
A solution of (2S)-2-(6-methoxy(2-naphthyl))propanoic acid (naproxen, 3.70 g, 16.1 mmol), (R)-(+)-3-benzyloxy-1,2-propanediol (2.92 g, 19.0 mmol), N,N-dimethylaminopyridine (DMAP, 0.40 g, 3.3 mmol) and 1,3-dicyclohexylcarbodiimide (3.61 g, 17.5 mmol) in CH2Cl2 (120 mL) was stirred at ambient temperature overnight. The byproduct, dicyclohexyl urea, was removed by filtration. The reaction mixture was partitioned between HCl (3N, 50 mL) and CH2Cl2 (50 mL×2). The combined organic extracts were back washed with water, brine, dried over Na2SO4, filtered, concentrated and dried under vacuum. The product was separated by silica gel column chromatography eluting with EtOAc:hexane (1:2, Rf=0.23) to give a mixture of the 1- and 2-glycerol ester isomers (88:12, 3.87 g). 1H NMR (300 MHz, CDCl3) δ 7.69-7.64 (m, 3H), 7.40-7.03 (m, 8H), 5.34 (s, 2H), 4.17-4.14 (m, 2H), 3.88 (s, 3H), 3.9-3.85 (m, 2H), 3.33-3.28 (m, 2H), 2.45 (br. d, 1H), 1.56 (d, J=7.2 Hz, 3H). 13C NMR (75 MHz, CDCl3) δ174.6, 157.6, 137.6, 135.4, 133.6, 129.6, 129.2, 128.8, 128.3, 127.7, 127.61, 127.55, 127.1, 126.1, 125.9, 119.0, 105.5, 73.3, 70.6, 68.8, 65.5, 62.2, 55.2, 45.3, 18.3. Mass spectrum (API-TIS) m/z 412 (M+NH4)+.
Workup
- customThe byproduct, dicyclohexyl urea, was removed by filtration
- customThe reaction mixture was partitioned between HCl (3N, 50 mL) and CH2Cl2 (50 mL×2)
- washThe combined organic extracts were back washed with water, brine
- dry with materialdried over Na2SO4
- filtrationfiltered
- concentrationconcentrated
- customdried under vacuum
- customThe product was separated by silica gel column chromatography
- washeluting with EtOAc:hexane (1:2, Rf=0.23)
- customto give
Sources & evidence
- ORD record
- ord-5ce18c6d8ff144eca29bef7670192c69
- Source dataset
- uspto-grants-2012_07
- Patent number
- US08222277B2
Reaction notes
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