2-Chloro-3-oxopentyl acetate → 2-Amino-4-methyl-5-hydroxyethylthiazole

Temperature

80 °C

2-(2-Amino-4-methyl-thiazol-5-yl)-ethanol was prepared according to general procedures presented hereinabove, by adding 20 grams (0.263 moles) of thiourea to 200 ml of dry toluene, followed by addition of 47 grams (0.263 moles) of 5-acetoxy-3-chloro-2-pentanone over a time period of 20 minutes. The reaction mixture was heated at 80° C. for 24 hours and thereafter approximately 180 ml of toluene were removed by evaporation. 180 ml of water and 20 ml of HCL solution (32%) were then added and the reaction mixture was refluxed for 1 hour at 90° C. The organic phase was then removed by washing with chloroform, and the aqueous phase was turned basic (pH 8-9) using a 5 N solution of sodium hydroxide. The product was extracted once with 70 ml chloroform and once with 70 ml ethyl acetate. The combined organic extracts were dried over sodium sulfate and the solvents were removed by evaporation to give 30 grams (72% yield) of violet-brown crystals.

1. customapproximately 180 ml of toluene were removed by evaporation
2. addition180 ml of water and 20 ml of HCL solution (32%) were then added
3. temperaturethe reaction mixture was refluxed for 1 hour at 90° C
4. customThe organic phase was then removed
5. washby washing with chloroform
6. extractionThe product was extracted once with 70 ml chloroform and once with 70 ml ethyl acetate
7. dry with materialThe combined organic extracts were dried over sodium sulfate
8. customthe solvents were removed by evaporation

ORD record

ord-d2b3e0b8d1334f7cb73bf12a5c35f31c

Source dataset

uspto-grants-2009_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07498445B2