反应详情

A solution of 3.95 g. (0.025 mole) of p-fluorobenzoyl chloride and 3.32 g. (0.025 mole) of aluminum chloride in 20 ml. of 1,2-dichloroethane is added dropwise to a solution of 4.52 g. (0.025 mole) of ethyl 1,4-dimethylpyrrole-2-acetate in 20 ml. of 1,2-dichloroethane at room temperature. The reaction mixture is stirred for 2 hours, and then cooled and poured into ice-dilute HCl. The organic phase is separated and washed successively with N,N-dimethyl-1,3-propanediamine, dilute hydrochloric acid and a saturated solution of sodium chloride; dried over anhydrous magnesium sulfate; and the solvent evaporated. The residue is triturated with hot hexane and crystals form upon cooling. There is obtained about 1.9 g. (25% yield) of ethyl 1,4-dimethyl-5-(p-fluorobenzoyl)-pyrrole-2-acetate as a white solid, m.p. 84-86° C. Upon recrystallization from methanol, the m.p. is 87-89° C.

1. customat room temperature
2. temperaturecooled
3. additionpoured into ice-dilute HCl
4. customThe organic phase is separated
5. washwashed successively with N,N-dimethyl-1,3-propanediamine, dilute hydrochloric acid
6. dry with materialdried over anhydrous magnesium sulfate
7. customand the solvent evaporated
8. customThe residue is triturated with hot hexane and crystals
9. customform
10. temperatureupon cooling
11. customThere is obtained about 1.9 g