Hydrochloric Acid → 5,6-Dimethylthieno[2,3-d]pyrimidine-2,4-diamine

Participants

Reaction Steps

A mixture of 2-amino-4,5-dimethylthiophene-3-carbonitrile (500 mg, 3.29 mmol), cyanoguanidine (276.6 mg, 3.29 mmol) and HCl (2 N, 1.5 mL) in water (10 mL) was refluxed under nitrogen for 2 h. The reaction mixture was cooled to room temperature, and basified with diluted NaOH aqueous solution to PH 7˜8. After evaporation of water, the residue was purified by preparative HPLC eluting with acetonitrile and water to give the title compound (33 mg, 5%). 1H NMR (400 MHz, DMSO-d6) δ 2.22 (s, 3H), 2.27 (s, 3H), 5.85 (bs, 2H), 6.29 (bs, 2H). MS 195 (MH+).

Provenance & Evidence