Tryptamine → HCID 86589512, compound

Participants

Reaction Steps

A solution of tryptamine (4.2 g, 26.2 mmol) in a 1:1 mixture of acetone; water is treated with di-t-butyl carbonate (6.5 g, 27.8 mmol) and K2CO3 (7.5 g, 54.4 mmol), stirred at room temperature for 16 h, concentrated in vacuo to an aqueous mixture and extracted with EtOAc. The extracts are combined, dried over MgSO4 and concentrated in vacuo. A mixture of the resultant residue (5.6 g, 21 mmol) and 6-chloroimidazo[2,1-b]thiazole-5-sulfonyl chloride (5.01 g, 19.5 mmol) in THF is treated portion-wise with potassium t-butoxide (4.3 g, 39 mmol (2 eq.) at room temperature, stirred for 16 h, poured into a saturated NaHCO3 solution and extracted with EtOAc. The extracts are combined, dried over MgSO4 and concentrated in vacuo. This resultant residue is chromatographed (silica gel, 10%-60% EtOAc in hexanes as gradient eluent) to give the protected 5-sulfonyl-tryptamine intermediate as a tan solid, 5.6 g (60% yield). A solution of said intermediate (6.8 g 14.2 mmol) in isopropanol is treated with 4N HCl in dioxane (40 mL, 11 equiv.), stirred for 4 h and filtered. The filtercake is washed with ether and air-dried to give the title product as an off-white solid 3.2 g (55% yield) mp 239-241° C., identified by NMR and mass spectral analyses.

Provenance & Evidence