反应详情

Ethyl 2-methyl-3-thiophenecarboxylate (3.42 g, 20.09 mmol; see step (ii) above) was dissolved in ethanol (5 mL) to which was added a solution of sodium hydroxide (3.2145 mg, 80.362 mmol) in water (10 mL). The reaction mixture was heated under reflux for 2 h. The volume was reduced to half under reduced pressure at 40° C. and the residue was cooled with ice water. Dilute HCl was added dropwise with stirring until pH 2. The white solid material was filtered off, washed with water and dried under reduced pressure at 50° C. to give the required material (2.1850 mg, 77% yield), m.p. 115-117° C., lit. m.p. 116-117° C. (see D. W. Knight, A. P. Nott J. Chem. Soc., Perkin Trans. 1 791-794 (1983)).

1. temperatureThe reaction mixture was heated
2. temperatureunder reflux for 2 h
3. customwas reduced to half under reduced pressure at 40° C.
4. filtrationThe white solid material was filtered off
5. washwashed with water
6. customdried under reduced pressure at 50° C.