ethyl 2-thiocyanatoacetate

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of cyclopropylmethylammonium acetate (0.45 g, 3.44 mmol) and thiocyanato-acetic acid ethyl ester (0.5 g, 3.44 mmol) was heated to 90° C. for 2 h. The reaction mixture was partitioned between 6N HCl and dichloromethane. The layers were separated. The aqueous layer was made basic by the addition of 6N ammonium hydroxide, and then extracted with dichloromethane. The organic layer was dried over sodium sulfate and concentrated under reduced pressure. The aqueous layer was also concentrated to dryness and the residue was triturated with DMF. The DMF solution was filtered and concentrated to dryness. The residues were combined and purified on a silica gel column with 100% ethyl acetate to afford 2-cyclopropylmethylamino-thiazol-4-one (275 mg, 47%). The reaction mixture was partitioned between 6N HCl and dichloromethane The layers were separated The aqueous layer was made basic by the addition of 6N ammonium hydroxide extracted with dichloromethane The organic layer was dried over sodium sulfate concentrated under reduced pressure The aqueous layer was also concentrated to dryness the residue was triturated with DMF The DMF solution was filtered concentrated to dryness purified on a silica gel column with 100% ethyl acetate

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of ethyl chloroacetate (20 g, 0.16 mol) and potassium thiocyanate (12.7 g, 0.13 mol) in ethanol (100 ml) was refluxed for 3 h. The solution was filtered and concentrated under reduced pressure to afford 18.7 g of thiocyanato-acetic acid ethyl ester (97%). A mixture of cyclopropylammonium acetate (0.50 g, 4.27 mmol) and thiocyanato-acetic acid ethyl ester (0.62 g, 4.27 mmol) was heated to 90° C. for 3 h, and left at rt overnight. The reaction mixture was partitioned between 6N HCl and dichloromethane. The layers were separated. The aqueous layer was made basic by the addition of 6N ammonium hydroxide, and then concentrated to dryness. The crude was triturated with dichloromethane and the solution separated from the solid by filtration. This solution was dried over sodium sulfate and concentrated to dryness. The crude was purified on a silica gel column with 100% ethyl acetate to afford 2-cyclopropylamino-thiazol-4-one (244 mg, 37%). The reaction mixture was partitioned between 6N HCl and dichloromethane The layers were separated The aqueous layer was made basic by the addition of 6N ammonium hydroxide concentrated to dryness The crude was triturated with dichloromethane the solution separated from the solid by filtration This solution was dried over sodium sulfate concentrated to dryness The crude was purified on a silica gel column with 100% ethyl acetate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of ethyl chloroacetate (20 g, 0.16 mol) and potassium thiocyanate (12.7 g, 0.13 mol) in ethanol (100 ml) was refluxed for 3 h. The solution was filtered and concentrated under reduced pressure to afford 18.7 g of thiocyanato-acetic acid ethyl ester (97%). A mixture of cyclopropylammonium acetate (0.50 g, 4.27 mmol) and thiocyanato-acetic acid ethyl ester (0.62 g, 4.27 mmol) was heated to 90° C. for 3 h, and left at rt overnight. The reaction mixture was partitioned between 6N HCl and dichloromethane. The layers were separated. The aqueous layer was made basic by the addition of 6N ammonium hydroxide, and then concentrated to dryness. The crude was triturated with dichloromethane and the solution separated from the solid by filtration. This solution was dried over sodium sulfate and concentrated to dryness. The crude was purified on a silica gel column with 100% ethyl acetate to afford 2-cyclopropylamino-thiazol-4-one (244 mg, 37%). The solution was filtered concentrated under reduced pressure