反应详情

温度

95 °C

A mixture of 2-bromo-1-(4-chlorobenzo[b]thiophen-2-yl)propan-1-one (0.5 g), 3,4,5,6-tetrahydro-2-pyrimidinethiol (0.144 g) and ethanol (8 ml) was heated under reflux for 20 minutes. Acetic acid (4 ml) was added, the mixture was heated under reflux for 18 hours then the solvents were removed in vacuo. 2.5M Sulphuric acid (10 ml) was added, the mixture was heated at 95° C. for 4.5 hours, then water (30 ml) was added and the mixture was basified to pH 7 by the addition of 5M aqueous sodium hydroxide solution. The product was extracted into dichloromethane (3×25 ml), the combined extracts were dried (MgSO4), and the solvent was removed in vacuo. The residue was dissolved in ethanol (20 ml) and hydrogen bromide (30% solution in acetic acid; 0.5 ml) was added. The solution was added dropwise to stirred ether (50 ml) and the resulting solid was collected by filtration and recrystallised from propan-2-ol (35 ml) to give 3-(4-chlorobenzo[b]thiophen-2-yl)-2-methyl-6,7-dihydro-5H-thiazolo[3,2-a]pyrimidine hydrobromide (0.2 g) as a white solid, m.p. 236-238° C.

1. temperaturewas heated
2. temperatureunder reflux for 20 minutes
3. temperaturethe mixture was heated
4. temperatureunder reflux for 18 hours
5. customthe solvents were removed in vacuo
6. addition2.5M Sulphuric acid (10 ml) was added
7. additionwater (30 ml) was added
8. additionthe mixture was basified to pH 7 by the addition of 5M aqueous sodium hydroxide solution
9. extractionThe product was extracted into dichloromethane (3×25 ml)
10. dry with materialthe combined extracts were dried (MgSO4)
11. customthe solvent was removed in vacuo
12. dissolutionThe residue was dissolved in ethanol (20 ml)
13. additionhydrogen bromide (30% solution in acetic acid; 0.5 ml) was added
14. additionThe solution was added dropwise
15. filtrationthe resulting solid was collected by filtration
16. customrecrystallised from propan-2-ol (35 ml)