4-Aminobiphenyl → 3-Methylthio-5-phenylindolin-2-one

Temperature

-65 °C

A solution of 21.4 g. (0.13 mole) of 4-aminobiphenyl in 400 ml. of methylene chloride was cooled to -65° C. and treated with 17.0 g. (0.13 mole) of ethyl 2-methylthioacetate and then 14.2 g. (0.132 mole) of t-butylhypochlorite while maintaining the temperature below -60° C. The reaction mixture was stirred at -65° C. for 1.5 hr., treated with 1.33 g. (0.132 mole) of triethyl amine and allowed to warm to ambient temperature. The solution was washed twice with water and concentrated. The residue was dissolved in 200 ml. of methanol, 40 ml. of 3N hydrochloric acid was added, and the mixture was refluxed over night. The solution was concentrated until a solid began to precipitate. The mixture was cooled, and the solid was collected by filtration, recrystallized once from methanol and twice from benzene to yield 6.0 g. (18%) of product as a white solid, m.p. 170°-2° C.

1. additiontreated with 17.0 g
2. addition, treated with 1.33 g
3. temperatureto warm to ambient temperature
4. washThe solution was washed twice with water
5. concentrationconcentrated
6. dissolutionThe residue was dissolved in 200 ml
7. additionof 3N hydrochloric acid was added
8. temperaturethe mixture was refluxed over night
9. concentrationThe solution was concentrated until a solid
10. customto precipitate
11. temperatureThe mixture was cooled
12. filtrationthe solid was collected by filtration
13. customrecrystallized once from methanol and twice from benzene
14. customto yield 6.0 g

ORD record

ord-4418dac1f471460890950535c9e08d27

Source dataset

uspto-grants-1987_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04670566