Diisopropylethylamine → HCID 18784692, compound

Participants

Reaction Steps

A stirred solution of 1'-methyl-5-(2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)biphenyl-4-carbonyl)-2,3,6,7-tetrahydrospiro[furo[2,3-f]indole-3,4'-piperidine] (E1, 350 mg, 0.67 mmole) in 1,2-dichloroethane (15 ml) under argon was treated with diisopropylethylamine (0.14 ml, 0.80 mmole) and 1-chloroethyl chloroformate (0.09 ml, 0.80 mmole). The mixture was stirred at room temperature for 2 h followed by 1 h at reflux temperature. Additional diisopropylethylamine (0.10 ml, 0.57 mmole) and 1-chloroethyl chloroformate (0.06 ml, 0.53 mmole) was added and reaction maintained at reflux for a further 1 h. The solution was concentrated in vacuo and the residue treated with methanol (20 ml) and heated under reflux for 1 h. The solution was concentrated in vacuo and the residue treated with conc. K2CO3 solution (25 ml) and chloroform (25 ml), shaken well and the chloroform solution separated, dried (Na2SO4) and concentrated in vacuo to afford the title compound as a beige solid (340 mg, 100%). The hydrochloride salt was prepared from acetone/ether as a white solid mp 203-210° C.

Provenance & Evidence