Allyl bromide → Prop-2-en-1-yl 1H-pyrrole-2-carboxylate

To a solution of 1H-pyrrole-2-carboxylic acid (1.5 g, 14 mmol) in N,N-dimethylformamide (50 mL) at 25° C. was added cesium carbonate (4.8 g, 14.7 mmol) and allyl bromide (1.34 mL, 15.4 mmol) and stirred for 16 h. The reaction mixture was treated with saturated aqueous ammonium chloride solution and diethyl ether (20 mL). The layers were separated and the aqueous layers were extracted with diethyl ether (3×100 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated in vacuo to afford the crude desired product, 1H-pyrrole-2-carboxylic acid allyl ester (1.6 g, 10.6 mmol, 76% yield) as a yellow oil, which was used in the next step without further purification. 1H NMR (400 MHz, CDCl3) δ 4.77 (1H, m), 5.35 (1H, dd, J1=10.4 Hz, J2=1.2 Hz), 5.39 (1H, dd, J1=16.8 Hz, J2=1.6 Hz), 6.26 (1H, m), 5.96 (1H, m), 6.94 (2H, m), 9.2 (1H, bs).

1. customThe layers were separated
2. extractionthe aqueous layers were extracted with diethyl ether (3×100 mL)
3. dry with materialThe combined organic layers were dried over magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo

ORD record

ord-8529cd686a674dbf858ce74e59771df4

Source dataset

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07842838B2