Sodium hydride → 1-amino-1H-pyrrole-2-carboxylic acid allyl ester

To a solution of 1H-pyrrole-2-carboxylic acid allyl ester (Example 1a, 0.75 g, 4.96 mmol) in N,N-dimethylformamide (20 mL) at 25° C. was added sodium hydride (0.316 g, 7.29 mmol) and stirred for 1 h. A solution of monochloroamine (36 mL, 7.19 mmol) in diethyl ether (0.2 M) was added and stirred for 1 h and then treated with saturated aqueous sodium bicarbonate solution (50 mL) and water (25 mL). The layers were separated and the aqueous layer was extracted with diethyl ether (3×50 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated in vacuo to afford the crude desired product, 1-amino-1H-pyrrole-2-carboxylic acid allyl ester (0.90 g) as a yellow oil, which was used in the next step without further purification. 1H NMR (400 MHz, CDCl3) δ 4.75 (2H, m), 5.28 (1H, dd, J1=10.0 Hz, J2=1.2 Hz), 5.40 (1H, dd, J1=17.2 Hz, J2=1.6 Hz), 6.03-5.90 (2H, m), 6.87 (1H, dd, J1=4.0 Hz, J2=1.6 Hz), 6.97 (1H, t, J=2.0 Hz).

1. stirringstirred for 1 h
2. customThe layers were separated
3. extractionthe aqueous layer was extracted with diethyl ether (3×50 mL)
4. dry with materialThe combined organic layers were dried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo

ORD record

ord-975e3eeb83c147f28c59b874182184ed

Source dataset

uspto-grants-2009_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07582754B2