4-Methoxybenzonitrile → 2-Methylthiophene-3-carboxylic acid

Temperature

-70 °C

To a solution of N-methyl-2-methylthiophene-3-carboxamide (36.0 g) in THF (500 ml) was added dropwise 2.5M n-BuLi/THF solution (200 ml) at −70° C. The reaction solution was stirred at −70° C. for 2 hr. followed by the addition of anisonitrile (31.0 g) at once. After the dry ice/acetone bath was removed, the reaction mixture was back to room temperature. Three hours later, an aqueous solution of saturated ammonium chloride and ether were added thereto, and then the mixture was further stirred for 1 hr. The resulting white precipitates were collected by filtration, washed with water, ether and n-hexane in this order, and then dried, to give the title compound (17.9 g, yield; 30%).

1. customAfter the dry ice/acetone bath was removed
2. customwas back to room temperature
3. additionThree hours later, an aqueous solution of saturated ammonium chloride and ether were added
4. stirringthe mixture was further stirred for 1 hr
5. customThe resulting white precipitates
6. filtrationwere collected by filtration
7. washwashed with water, ether and n-hexane in this order
8. customdried

ORD record

ord-7bf24ba0fab24010b7cc10e1928deda1

Source dataset

uspto-grants-2005_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06875761B2