Methyl 5-methyl-4-nitrothiophene-2-carboxylate → Methyl 4-amino-5-methylthiophene-2-carboxylate

To a solution of methyl 5-methyl-4-nitrothiophene-2-carboxylate (F-3) (14.8 g, 73.6 mmol) in MeOH/THF (1:1, 300 mL) was added Raney Ni. The reaction mixture was degassed and charged with hydrogen 3 times, and then stirred at room temperature for 36 h under 1 atmosphere of hydrogen. Raney Ni was filtered, and the filtrate was concentrated. The residue was treated with aqueous HCl (1 N, 150 mL) and filtered. The filtrate was treated with aqueous NaOH (1 N) to bring pH to about 8 to 9. Then the mixture was extracted with ethyl acetate. The combined organic layers were dried over Na2SO4, and the solvent was removed to give the title compound (8.1 g).

1. customThe reaction mixture was degassed
2. additioncharged with hydrogen 3 times
3. filtrationRaney Ni was filtered
4. concentrationthe filtrate was concentrated
5. additionThe residue was treated with aqueous HCl (1 N, 150 mL)
6. filtrationfiltered
7. additionThe filtrate was treated with aqueous NaOH (1 N)
8. extractionThen the mixture was extracted with ethyl acetate
9. dry with materialThe combined organic layers were dried over Na2SO4
10. customthe solvent was removed

ORD record

ord-205a3e312cf948db8d02c967d690a325

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08987269B2