Ethylenediamine → HCID 11218424, compound

Participants

Reaction Steps

A suspension of methyl 1H-indole-2-carboxylate (5.0 g) and sodium hydride (60% dispersion in oil, 1.3 g) in dry dimethylsulphoxide was stirred at 60° C. for 30 minutes. The reaction mixture was cooled to room temperature before adding 1-bromopropane (2.85 ml) and then heated at 60°-80° C. for 3 hours. The cooled reaction mixture was poured into dilute hydrochloric acid and extracted with diethyl ether. The combined organic extracts were washed with water, dried (MgSO4) and the solvent removed in vacuo. The crude product was purified by chromatography on silica, and elution with 10% v/v diethyl ether in petroleum ether (bp 40°-60° C.) gave methyl 1-propyl-1H-indole-2-carboxylate (5.23 g) as a clear oil; NMR (CDCl3) δ0.93 (3H,t,J=7 Hz, C--CH3), 1.82 (2H, sext,J=7 Hz,C--CH2 --C), 3.89 (3H,s,OCH3), 4.52 (2H,t,J=7 Hz, N--CH2), 7.15 (4H,m,Ar--H), 7.67 (1H,m,Ar--H). The ester was converted to 2-(2-imidazolin-2-yl)-1-propyl-1H-indole hydrochloride using trimethylaluminium and ethylenediamine as described in Example 1(a); mp 186.5°-187° C.

Provenance & Evidence