Ethanol → Ethyl 2-amino-4,5,6,7-tetrahydro-1,3-benzothiazole-6-carboxylate hydrobromide

Temperatur

0 °C

A 3 liter reactor equipped with mechanical stirrer, thermometer and condenser was loaded with 1500 ml of ethanol and 200 g of 4-oxo-cyclohexanecarboxylic acid ethyl ester. After cooling to 0° C., 188 g of bromine were dropped therein in about 1 hour. The temperature was raised to 10° C., then to the room one after discolouration. After 1 hour, 89.32 g of thiourea were added in portions to obtain a suspension, that was refluxed to obtain gradual dissolution of the solid. After 4 hours the solution was concentrated to small volume to obtain a solid mass, that was suspended in 800 ml of acetone and refluxed to obtain a solution. The solution was then cooled to room temperature to precipitate a solid, then to 0° C. and after 4 hours the solid was filtered, washed twice with 100 ml of cold acetone and dried to obtain 170 g of the title product.

1. customA 3 liter reactor equipped with mechanical stirrer
2. temperatureThe temperature was raised to 10° C.
3. waitAfter 1 hour
4. customto obtain a suspension, that
5. temperaturewas refluxed
6. customto obtain gradual
7. dissolutiondissolution of the solid
8. concentrationAfter 4 hours the solution was concentrated to small volume
9. customto obtain a solid mass, that
10. temperaturerefluxed
11. customto obtain a solution
12. temperatureThe solution was then cooled to room temperature
13. customto precipitate a solid
14. filtrationto 0° C. and after 4 hours the solid was filtered
15. washwashed twice with 100 ml of cold acetone
16. customdried

ORD-Eintrag

ord-36d9fa800331458bb2edcf0bb26dcc5f

Quelldatensatz

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07741490B2