Propylamine → 5-Nitro-N-propyl-2-thiophenecarboxamide

To a solution of 5-nitro-2-thiophenecarboxylic acid (967 mg, 5.59 mmol) in DMF (0.745 ml) and CH2Cl2 (4 ml) was added oxalyl chloride at 0° C. After stirring for 0.5 h at rt (room temperature), the solvent was evaporated below 30° C. to give yellow oil and solid. To a solution of n-propylamine (0.551 ml, 6.71 mmol) in Et3N (1.87 ml, 13.4 mmol) and CH2Cl2 (25 ml) was added a solution of crude acid chloride in CH2Cl2 (10 ml) below 20° C. After stirring for 4 h at rt, the mixture was washed with water, saturated NaHCO3 aqueous solution, water, brine, dried (a2SO4), and concentrated to give brown solid, which was purified by column chromatography (silica gel 50 g, CH2Cl2/MeOH=100/1-30/1) to afford 815 mg (68%) of white solid.

1. customthe solvent was evaporated below 30° C.
2. customto give yellow oil and solid
3. stirringAfter stirring for 4 h at rt
4. washthe mixture was washed with water, saturated NaHCO3 aqueous solution, water, brine
5. customdried (a2SO4)
6. concentrationconcentrated
7. customto give brown solid, which
8. customwas purified by column chromatography (silica gel 50 g, CH2Cl2/MeOH=100/1-30/1)

ORD record

ord-67e748bfdb6e4240b510087e7a1fa050

Source dataset

uspto-grants-2001_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06307061B2