Triethylamine → HCID 11040790, compound

Participants

Reaction Conditions

Reaction Steps

L-Proline (11.5 g, 0.10 mol) was added to a 500 ml three neck flask fitted with a 125 ml addition funnel, thermometer and a nitrogen inlet tube. To the flask was added dry tetrahydrofuran (115 ml) and the mixture cooled to 15° C. using an ice/water bath. The addition funnel was charged with diphosgene (7.2 ml, 0.06 mol) and dry THF(50 ml). The diphosgene solution was added dropwise to the proline mixture over 45 minutes while maintaining a reaction mixture temperature in the range of 15° to 20° C. Once the addition was complete the mixture was warmed to 35° C. for 1 hour. At the end of this time a clear and colorless solution was obtained. The reaction mixture was then cooled to room temperature and concentrated under vacuum to a volume of approximately 50 ml. The residue was redissolved in 115 ml of THF and cooled to 0°-5° C. using an ice bath. Triethylamine (12 ml, 0.086 mol) was added dropwise to the cooled solution over 30 minutes. The solution was stirred a further 30 minutes after which time the solids were filtered and washed with THF(100 ml). The organics were concentrated under reduced pressure to give the desired compound (4) (14 g, 99%) as a light beige solid. The material was stored under nitrogen at -78° C. in order to avoid decomposition, and used without further purification in subsequent reactions.

Provenance & Evidence