Preparation and application of 3-benzoylpyrrole_Kain Industrial Additive

Overview^[1]

3-Benzoypyrrole is a heterocyclic organic compound that can be used as an intermediate in pharmaceutical synthesis.

Structure

Preparation^[1]

3-Benzoypyrrole is prepared as follows: to a stirred suspension of sodium hydride (8.0g) in 200ml anhydrous ether, phenyl vinyl ketone (13.22g) and tosylmethyl isocyanate are added dropwise. A solution of compound (19.52) in 150 ml anhydrous methyl sulfoxide and 300 ml anhydrous ether. At this rate, Israel is returning modestly. After the addition is complete, the suspension is stirred at room temperature for 30 minutes, and then 200 ml of water is added dropwise for hydrolysis. The ether layer was separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water, 0.1N sulfuric acid, and then with water. The organic phase was dried over magnesium sulfate, filtered and evaporated in vacuo. The residue was purified by flash column chromatography (silica gel, DCM/ethyl acetate, 5:1). The desired fractions were concentrated and the remaining oil was crystallized from DCM/hexane to give the crystalline product 3-benzoylpyrrole (7.11 g), m.p. 205°C. 98°-99°C (ignition*m.p. 96°-97°C).

Apply^[1]

3-Benzoypyrrole can be used as a pharmaceutical synthesis intermediate. To prepare (1-amino-1H-pyrrol-3-yl)phenylmethanone: To a solution of 3-benzoylpyrrole (4.92g) in 50ml anhydrous dimethylformamide, add ground potassium hydroxide (8.06 g). With stirring at room temperature, hydroxylamine-O-sulfonic acid (4.23 g) was added to the suspension in 4 portions over 1 hour. After the addition was complete, the reaction mixture was stirred at room temperature for 30 minutes, then diluted with 50 ml of water and extracted with DCM. The combined organic layers were washed with water, dried over magnesium sulfate and evaporated in vacuo. The residue was purified by flash column chromatography (silica gel, DCM/ethyl acetate, 5:1) to obtain the starting material (1.44 g) and the desired product as the second fraction. Recrystallization from diethyl ether/hexane gave a crystal product (1.80 g), which was combined with the material from the 36.9 mmol scale reaction and recrystallized from DCM/hexane to give 3.20 g of crystals, m.p. 82°-83°C analysis: Calculated value for C11H10N2O: 70.95% C, 5.41% H, 15.04% N; Found value: 70.65% C, 5.49% H, 14.97% N.