N-methyl-2-pyrrolidone → 5-Phenylthiophen-3-amine

Temperature

160 °C

A mixture of methyl 3-amino-5-phenylthiophene-2-carboxylate (2.50 g, 10.7 mmol), 3.5 mL of N-methylpiperazine and 12 mL of N-methylpyrrolidinone is heated at 160° C. for 4 hours. The reaction mixture is cooled to room temperature and poured into 100 mL of water. The solids are collected by filtration washing with 50 mL of water. Ethyl acetate and hexane are added and the filtrate is decanted off from the gummy black residue. The filtrate is concentrated to provide 850 mg of 5-phenyl-3-thienylamine as a yellow solid, mp 76–78° C.; 1H NMR (DMSO-d6) δ 4.87 (s, 2H), 5.98 (d, J=1.5 Hz, 1H), 6.95 (d, J=1.5 Hz, 1H), 7.28 (m, 1H), 7.37 (t, J=7 Hz, 2H), 7.53 (d, J=7 Hz, 2H); MS 176.2 (M+H)+.

1. temperatureThe reaction mixture is cooled to room temperature
2. filtrationThe solids are collected by filtration
3. washwashing with 50 mL of water
4. additionEthyl acetate and hexane are added
5. customthe filtrate is decanted off from the gummy black residue
6. concentrationThe filtrate is concentrated

ORD record

ord-8b5d10bfc98d4a0c8e42ad35f133f848

Source dataset

uspto-grants-2007_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07276519B2