Cyanoacetic acid → HCID 19071304, compound

Participants

Reaction Steps

A solution of cyanoacetic acid (Aldrich, 1.23 g, 14.3 mmol) and 1,3-bis(cyclohexylmethyl)thiourea (from step (a), 3.50 g, 13.0 mmol) in acetic anhydride (8.1 mL) was stirred at 70° C. for 2 h under nitrogen. Volatiles were removed in vacuo and the residual oil was dried by evaporation of portions of 10% water-ethanol (3×50 mL). The resulting solids were dissolved in ethanol (12 mL)-water (28 mL) at reflux with adjustment of the pH to 11 by addition of 10% aqueous sodium carbonate. After 1 h, the mixture was cooled to ambient temperature, volatiles were removed under vacuum, and the residue was chromatographed on silica gel. 6-Amino-1,3-bis(cyclohexylmethyl)-1,2-dihydro-2-thioxo-4(3H)-pyrimidinone eluted with 4% methanol in chloroform, and was recrystallized from 2% ethyl acetate in hexanes to provide an off-white powder (2.27 g, 50%), m.p. 147°-150° C.; 1H-NMR (DMSO-d6) consistent with structure.

Provenance & Evidence