反应详情

4,5-Dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylic acid (0.47 g) was suspended in tetrahydrofuran (15 ml); oxalyl chloride (0.32 g) and then N,N-dimethylformamide (6 μl) were added. After this mixture was stirred at room temperature for 2 hours, it was concentrated under reduced pressure. The residue was suspended in tetrahydrofuran (5 ml) and cooled with ice; concentrated aqueous ammonia (4.0 ml) was added. After the reaction mixture was stirred at room temperature for 1 hour, it was poured over water (150 ml) and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water and dried (MgSO4), after which the solvent was distilled off to yield 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxamide (0.27 g, 57%), which was then recrystallized from chloroform-methanol. Light-yellow needles. Melting point over 300° C.

1. concentrationit was concentrated under reduced pressure
2. temperaturecooled with ice
3. additionconcentrated aqueous ammonia (4.0 ml) was added
4. stirringAfter the reaction mixture was stirred at room temperature for 1 hour
5. additionit was poured over water (150 ml)
6. extractionextracted with ethyl acetate-tetrahydrofuran (3:1
7. washThe organic layer was washed with water
8. dry with materialdried (MgSO4)
9. distillationafter which the solvent was distilled off