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ChemicalBook CAS DataBase List (+)-D-PYROGLUTAMOL P-TOLUENESULFONATE
128899-31-0

(+)-D-PYROGLUTAMOL P-TOLUENESULFONATE synthesis

6synthesis methods
-

Yield:128899-31-0 81%

Reaction Conditions:

with N,N-dimethyl-4-aminopyridine;triethylamine in dichloromethane at 20; for 18 h;Cooling with ice;

Steps:

45 Preparation 45: (R)-5-(hydroxymethyl)-2-pyrrolidinone p-toluenesulfonate

(R)-(-)-5-(hydroxymethyl)-2-pyrrolidinone (1.0 g, 8.7 mmol, 1.0 equiv.) was dissolved in methylene chloride (40 mL). Triethylamine (1.569 mL, 11.3 mmol, 1.3 equiv.), p-toluenesulfonyl chloride (1.904 g, 10.0 mmol, 1.1 equiv.) and 4-(dimethylamino)pyridine (0.12 g) were added under ice-cooling, and the mixture stirred at room temperature for 18 hrs. The reaction mixture was concentrated under reduced pressure, 0.5 N aqueous hydrochloric acid was added, and the mixture extracted with ethyl acetate. The organic layer was washed with 0.5 N aqueous hydrochloric acid, water, saturated aqueous sodium hydrogen carbonate, and saturated aqueous sodium chloride. The organic fraction was dried (anhydrous sodium sulfate), filtered and concentrated under reduced pressure to afford a white solid (1.91 g, 81%). 1H NMR (300 MHz, CDCl3): δ 7.79-7.76 (m, 2H), 7.38-7.35 (m, 2H), 5.73 (br s, 1H), 4.08-4.04 (dd, 1H, J=3.5, 9.5 Hz), 3.98-3.93 (m, 1H), 3.85-3.82 (dd, 1H, J=7.5, 9.5 Hz), 2.47 (s, 3H), 2.36-2.22 (m, 3H), 1.81-1.73 (m, 1H).

References:

US2015/284362,2015,A1 Location in patent:Paragraph 0360