Ethylenediamine → HCID 57637387, compound

Participants

Reaction Conditions

Reaction Steps

A portion of this mixture of 5-(3-methoxy-phenyl)-1-(2-trimethylsilanyl-ethoxymethyl)-1H-thieno[3,2-c]pyrazole and 5-(3-methoxy-phenyl)-2-(2-trimethylsilanyl-ethoxymethyl)-2H-thieno[3,2-c]pyrazole (4.41 g, 12.2 mmol) and ethylenediamine (2.50 mL, 37.0 mmol) at room temperature under nitrogen was added tetrabutylammonium fluoride (61.0 mL of a 1 M tetrahydrofuran solution, 61.0 mmol) and the resulting solution heated at 70° C. After 21.5 hours, the reaction was cooled to room temperature and the solvent removed in vacuo. Water (150 mL) was added to the residue and the aqueous mixture extracted twice with ethyl acetate (100 mL). The combined extracts were washed with water (75 mL) and brine (75 mL) successively, dried over magnesium sulfate, and concentrated to give 5-(3-methoxy-phenyl)-1H-thieno[3,2-c]pyrazole [2.47 g, 87%, Intermediate (53)] as an off-white solid: TLC Rf 0.45 (silica, ethyl acetate); LC/MS: 231.0 (M+H), RT=3.20 minutes; 1H NMR (300 Mhz, CDCl3) δ 10.65 (br s, 1H), 7.78 (s, 1H), 7.32 (m, 1H), 7.25-7.21 (m, 2H), 7.16 (m, 1H), 6.89 (m, 1H), 3.86 (s, 3H).

Provenance & Evidence