反应详情

温度

-15 °C

50 ml of conc. hydrochloric acid are added to methyl 4-amino-3-methylbenzoate (10 g, 61 mmol) and the mixture is cooled down to −15° C. A solution of sodium nitrite (6.3 g, 91 mmol) in 50 ml of water is added dropwise in such a way that the temperature does not exceed −5° C. After stirring at −10° C. for 4 h, a solution of tin(II) chloride dihydrate in 50 ml of conc. hydrochloric acid is added dropwise to the suspension, with the reaction temperature not exceeding −5° C. The viscous suspension is stirred at RT for 15 h before it is adjusted to pH 14 with 200 ml of sodium hydroxide solution (10 N). The reaction mixture is filtered through kieselguhr and Extrelut® (60 g) and rinsed with 2 l of chloroform. The organic phase which is obtained is washed with water (2×200 ml), dried over sodium sulphate and evaporated in vacuo. The residue is stirred up with 120 ml of petroleum ether and filtered. Yield: 6.3 g

1. customdoes not exceed −5° C
2. customexceeding −5° C
3. stirringThe viscous suspension is stirred at RT for 15 h before it
4. filtrationThe reaction mixture is filtered through kieselguhr and Extrelut® (60 g)
5. washrinsed with 2 l of chloroform
6. customThe organic phase which is obtained
7. washis washed with water (2×200 ml)
8. dry with materialdried over sodium sulphate
9. customevaporated in vacuo
10. stirringThe residue is stirred up with 120 ml of petroleum ether
11. filtrationfiltered