[CH3:1][C:2]1[O:3][C:4]2[C:5](=[CH:7][S:8][CH:9]=2)[N:6]=1.C(=O)=O.[Br:13]N1C(=O)CCC1=O.[Cl-].[Na+]>O1CCCC1>[Br:13][C:9]1[S:8][CH:7]=[C:5]2[C:4]=1[O:3][C:2]([CH3:1])=[N:6]21 mmol of 2-methylthieno[3,4-d][1,3]oxazole was dissolved in 10 ml of tetrahydrofuran and the temperature was kept at −78° C. in a methanol bath cooled by dry ice. A solution in which 1.05 mmol of N-bromosuccinimide was dissolved in 5 ml of tetrahydrofuran was gradually added dropwise to carry out the reaction for 2 hours. Then an excess amount of saturated sodium chloride aqueous solution was added to stop the reaction. The reacted liquid was washed with water. Then the organic layer was recovered and dried under sodium sulfate. The solvent was evaporated out. The product was purified using column separation with the solvent of ethylacetate and hexane, obtaining 6-bromo-2-methylthieno[3,4-d][1,3]oxazole represented by formula (21).
Wird geladen…
