反应详情

A solution of 1.19 g of 2-amino-5-(4-chlorophenyl)-3-nitro-pyridine in 17 ml of ethanol is treated with 5.5 g of SnCl2.2H2O at 90° C. for 17 h under a nitrogen atmosphere. Thereafter, the solution is concentrated in vacuo to dryness. The residue is dissolved in 300 ml of water and adjusted to pH 8 using a 1.0 M solution of aqueous sodium hydroxide. Subsequently, the aqueous layer is extracted four times each with 50 ml of ethyl acetate. The combined organic phases are extracted once with 50 ml of brine, dried using MgSO4, filtered with suction, and evaporated to dryness to yield 1.05 g of the pure title compound of m.p. 178° C. MS: 220.3 (MH+). MS: 220.3/222.3 (MH+, 100%/20%). TLC: Rf=0.30 (dichloromethane/methanol 5:1).

1. concentrationThereafter, the solution is concentrated in vacuo to dryness
2. dissolutionThe residue is dissolved in 300 ml of water
3. extractionSubsequently, the aqueous layer is extracted four times each with 50 ml of ethyl acetate
4. extractionThe combined organic phases are extracted once with 50 ml of brine
5. customdried
6. filtrationfiltered with suction
7. customevaporated to dryness