Imidazole → O-methyl-N-trityl-D-serine

Participants

Reaction Steps

To the stirred and cooled (at −15° C. to −10° C.) suspension of tetrahydrofuran (250 ml), imidazole (1.95 g) and sodium hydride (12.66 g), solid N-trityl-D-serine (50 g) was added in lots at an interval of 10 minutes. It was stirred for 45 minutes at −15° C. to −10° C. and then methyl iodide (40.85 g) was added to it at the same temperature (mild exothermic reaction was observed). The temperature of the reaction mass was raised to −5° C. to 0° C. and then it was stirred for 3 hours at the same temperature. De-ionized water (100 ml) was added to it and the reaction mass was cooled to 0° C. to 5° C. Acetic acid (9.8 ml) was added to the reaction mass and pH of the mass was adjusted to 6.5 to 7.0. Tetrahydrofuran was recovered completely under vacuum at 30° C. to 35° C. and dichloromethane (100 ml) and de-ionized water (100 ml) were added to the reaction mass at ambient temperature. This was stirred and allowed to settle for 15 minutes. The layers were separated. Dichloromethane (50 ml×2) was added to the aqueous layer, stirred, allowed to settle and layers were separated. The obtained organic layers were combined and de-ionized water (100 ml) was added to it. This was stirred, allowed to settle and then organic layer was separated. Anhydrous sodium sulphate (5 g) was added to the organic layer. It was stirred for 20 minutes and filtered through hyflo bed.

Provenance & Evidence