反应详情

A mechanically stirred solution of aniline (139.7 g, 1.5 mole) in pyridine (2 liters), under N2 is cooled in an icebath. Methanesulfonyl chloride (171.8 g, 1.5 mole) is added dropwise to this solution while the temperature is maintained at 15°-20° C., which results in a red-orange color change in the reaction mixture. After the addition is complete the ice bath is removed and the reaction is allowed to continue at ambient temperature. By TLC on silica gel (2.5% MeOH:CH2Cl2) the reaction is complete after 21/2 hours. The reaction mixture is concentrated in vacuo and the residue is combined with 700 ml of water which results in crystallization of a dark red material. This material is filtered and washed several times with water. The filtered material is dissolved in CH2Cl2, washed with brine, dried (Na2SO4), and concentrated in vacuo. The residue is dissolved in hot ethyl acetate, treated with Darco (decolorizing carbon) and crystallized to yield four crops of methanesulfonanilide 157.37 g, 19.27 g, 26.55 g, 5.07 g which had a mp: 93°-94° C.

1. temperatureis maintained at 15°-20° C.
2. customwhich results in a red-orange color change in the reaction mixture
3. additionAfter the addition
4. customis removed
5. customto continue at ambient temperature
6. custom2 hours
7. concentrationThe reaction mixture is concentrated in vacuo
8. customresults in crystallization of a dark red material
9. filtrationThis material is filtered
10. washwashed several times with water
11. dissolutionThe filtered material is dissolved in CH2Cl2
12. washwashed with brine
13. dry with materialdried (Na2SO4)
14. concentrationconcentrated in vacuo
15. dissolutionThe residue is dissolved in hot ethyl acetate
16. additiontreated with Darco (decolorizing carbon)
17. customcrystallized