Triethylamine → HCID 178525393, compound

Participants

Reaction Steps

To a stirred suspension of sodium hydride (200 mg of 60% dispersion; 5.0 mmol) in dry tetrahydrofuran (25 mL), was added portionwise alcohol hydrochloride (4) (1.05 g; 2.5 mmol) over a period of 10 min. The resultant suspension was stirred at room temperature for 3.5 h. The piperazine derivative (8) (706 mg; 2.25 mmol) was added, the mixture was diluted with dry tetrahydrofuran (25 mL), and the resultant suspension allowed to stir overnight at room temperature. Triethylamine (0.35 mL; 2.5 mmol) was added, followed by the addition over about 4 min. of a solution of triphosgene (252 mg; 0.849 mmol) in dry dichloromethane (2.5 mL) (mild exotherm). The resultant suspension was stirred at room temperature for 6 h; then the solids were filtered and washed with ethyl acetate. The filtrate and washings were combined, and solvent removed under reduced pressure. Chromatography of the residue on silica gel, eluting with a gradient of ethyl acetate-methanol (98:2→95:5), yielded the title tritylated product (31) as a white glassy foam. ESIMS: 722 (MH+; 85%); 243 (Ph3C+; 100%). [A more polar fraction corresponding to symmetrical urea (30) was also isolated.]

Provenance & Evidence