Chlorotrimethylsilane → N-(Triphenylmethyl)-D-serine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To the solution of D-Serine (100 g; 0.95 moles) in dichloromethane (1.0 L), trimethylsilyl chloride (361.79 g) was added in 15 minutes to 30 minutes. It was refluxed at 40° C. for 20 minutes and then cooled to ambient temperature. To the resultant solution, triethyl amine (433.27 g) dissolved in dichloromethane (200 ml) was added in 60 minutes to 90 minutes. It was refluxed at 40° C. to 45° C. for 2 hours and then cooled to 0° C. to −2° C. To the cooled solution, methanol (45.72 g) diluted with dichloromethane (200 ml) was added in 60 minutes to 75 minutes (exothermic reaction was observed). It was stirred for 15 minutes at 0° C. to 5° C. and then further raised to ambient temperature. At this temperature, triethyl amine (96.28 g) was added in 15 minutes to 20 minutes and stirred for 10 minutes. To the resultant reaction mixture, trityl chloride (238.78 g; 0.85 moles) was added in 6 lots at an interval of 10 minutes at ambient temperature and stirred for 3 hours. The reaction mixture was cooled to 5° C. and de-ionized water (500 ml) was added to it at 5° C. to 10° C. The reaction mixture was stirred for 15 minutes at the same temperature and allowed to settle for 15 minutes. The organic layer (dichloromethane layer) was separated and 5% citric acid monohydrate solution (500 ml) was added for 5 minutes to 10 minutes, stirred for 15 minutes at 5° C. to 10° C. and allowed to settle for 15 minutes. The organic layer (dichloromethane layer) was separated and de-ionized water (500 ml) was added at 5° C. to 10° C. for 10 minutes to 15 minutes, stirred for 15 minutes and allowed to settle. The organic layer obtained was separated and solvent was recovered at atmospheric pressure up to 45° C. Traces of solvent (if any) were recovered under vacuum at 35° C. to 40° C. To the remaining residue, toluene (100 ml) was added and heated to 50° C. under stirring for 15 minutes. The solvent was recovered under vacuum at 45° C. to 50° C. Toluene (250 ml) was again added to the residue at 50° C. and it was stirred for 15 minutes. This was cooled to ambient temperature and then hexanes (500 ml) were added. The mixture was stirred for 30 minutes and cooled further to 0° C. to 5° C. It was stirred at this temperature for 30 minutes. The solid obtained was filtered, washed with hexanes (200 ml) and suck dried. It was further dried in a vacuum tray dryer at 50° C. to 55° C. until moisture content was NMT 0.5%.

Herkunft & Nachweise