Réaction #46957

Équation de réaction

thiourea

ethanol

4-oxo-cyclohexanecarboxylic acid ethyl ester

bromine

→

title product

Rendement 47.2%

2-Amino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid ethyl ester hydrobromide

Rendement 47.2%

Solvants

acetone

Conditions de réaction

Traitement

1. 1
   AutreA 3 liter reactor equipped with mechanical stirrer
2. 2
   TempératureThe temperature was raised to 10° C.
3. 3
   workup.WAITAfter 1 hour
4. 4
   Autreto obtain a suspension, that
5. 5
   Températurewas refluxed
6. 6
   Autreto obtain gradual
7. 7
   workup.DISSOLUTIONdissolution of the solid
8. 8
   ConcentrationAfter 4 hours the solution was concentrated to small volume
9. 9
   Autreto obtain a solid mass, that
10. 10
    Températurerefluxed
11. 11
    Autreto obtain a solution
12. 12
    TempératureThe solution was then cooled to room temperature
13. 13
    Autreto precipitate a solid
14. 14
    Filtrationto 0° C. and after 4 hours the solid was filtered
15. 15
    Lavagewashed twice with 100 ml of cold acetone
16. 16
    Autredried

Mode opératoire

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.

Source