Potassium Carbonate → 2-Amino-4-methyl-5-(3-pyridyl)thiazole

To a solution of 1-(3-pyridyl)-2-propanone (3.4 g) in methylene chloride (30 ml) was dropwise added a solution of sulfuryl chloride (4.0 g) in methylene chloride (5 ml) at 20° C. to 28° C. under stirring and the mixture was stirred at ambient temperature for 30 minutes. The resulting mixture was added to a solution of thiourea (4.2 g) in a mixture of tetrahydrofuran (50 ml) and water (20 ml) and the mixture was adjusted to pH 7.0 to 7.5 with 20% aqueous potassium carbonate. After being stirred at ambient temperature for 2 hours, the mixture was evaporated in vacuo. The residue was dissolved in a mixture water and ethyl acetate, and the mixture was acidified to pH 1.0 with 10% hydrochloric acid. The separated aqueous layer was adjusted to pH 7.5 with 20% aqueous potassium carbonate and extracted with ethyl acetate. The ethyl acetate layer was washed with brine and dried over magnesium sulfate. The solvent was evaporated in vacuo. The residue was washed with a mixture of diethyl ether and ethyl acetate, and recrystallized from tetrahydrofuran to give 2-amino-4-methyl-5-(3-pyridyl)thiazole (1.9 g). mp 190°-191° C.

1. stirringthe mixture was stirred at ambient temperature for 30 minutes
2. stirringAfter being stirred at ambient temperature for 2 hours
3. customthe mixture was evaporated in vacuo
4. dissolutionThe residue was dissolved in a mixture water and ethyl acetate
5. extractionextracted with ethyl acetate
6. washThe ethyl acetate layer was washed with brine
7. dry with materialdried over magnesium sulfate
8. customThe solvent was evaporated in vacuo
9. washThe residue was washed with a mixture of diethyl ether and ethyl acetate
10. customrecrystallized from tetrahydrofuran

ORDレコード

ord-f847839cdc894c4fb5e8ecc6c8bcf6b3

出典データセット

uspto-grants-1987_03

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US04649146