(R)-camphorsulfonic acid → HCID 86668042, compound
Reaction equation
[CH2:1]([O:3][C:4](=[O:17])[C:5]([C:10]1[CH:15]=[CH:14][N:13]=[C:12]([Br:16])[CH:11]=1)([CH2:8][OH:9])[CH2:6][OH:7])[CH3:2].[C@@:18]12(CS(O)(=O)=O)C(C)(C)C(C[CH2:24]1)C[C:19]2=O>CN(C=O)C>[CH2:1]([O:3][C:4]([C:5]1([C:10]2[CH:15]=[CH:14][N:13]=[C:12]([Br:16])[CH:11]=2)[CH2:8][O:9][C:18]([CH3:24])([CH3:19])[O:7][CH2:6]1)=[O:17])[CH3:2]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 80 °C
Procedure
A mixture of 2-(2-bromo-pyridin-4-yl)-3-hydroxy-2-hydroxymethyl-propionic acid ethyl ester (30.0 g, 98.6 mmol) 2,2-dimethoxy propane (51.11 g, [60.5 ml], 493.1 mmol) and (1R)-(−)-10-camphor sulphonic acid (5.72 g, 24.65 mmol) in DMF (100 ml) was heated at 80° C. for 10 h. Reaction mixture was cooled to rt and concentrated under reduced pressure. The residue was dissolved in ethyl acetate and worked up by washing with water, brine, followed by drying over anhy. Na2SO4. Organic layer was concentrated under reduced pressure and the crude product was purified by column chromatography using 10% ethyl acetate in Hexane to obtain title compound as a yellow solid. Yield=18.15 g (53%). TLC (30% ethyl acetate in hexane) Rf=0.52; LCMS: RtH7=1.487; [M+1]+=344.0 and 346.0; HPLC RtH9=7.6 min (74%); 1H NMR (300 MHz, CDCl3): b 8.41-8.34 (t, 1H), 7.54 (s, 1H), 7.32-7.28 (m, 1H), 4.51 (dd, 2H), 4.27-4.21 (q, 4H), 1.45 (s, 3H), 1.39 (s, 3H), 1.23 (t, 3H).