Hydrochloric Acid → 1-(6-Chloro-pyrido[2,3-b]pyrazin-3-yl)-3-ethyl-thiourea

Participants

Reaction Steps

A total of 5.0 g 6-Chloro-pyrido[2,3-b]pyrazin-3-ylamine (27.7 mmol; 1 eq) was dissolved in 150 mL of dry DMF. 1.32 g NaH (60% dispersion in mineral oil; 33.2 mmol; 1.2 eq) was added and the dark brown solution was stirred at room temperature for 1 hour. 2.4 g (27.7 mmol; 1 eq) ethyl isothiocyanate was then added and the resulting mixture was stirred at room temperature for 3 h. The reaction mixture was then poured into 500 mL of water. The solution was neutralized with 1 N HCl whereas the product crystallizes. The brown solid was filtered of and recrystallised from dichloromethane/diethyl ether to afford 3.6 g (48.5% yield) of 1-(6-Chloro-pyrido[2,3-b]pyrazin-3-yl)-3-ethyl-thiourea.

Provenance & Evidence