反应详情

A solution of the diamine of Step A (7.1 g) in dioxane (250 mL) and 1,1′-thiocarbonyldiimidazole (5.6 g) was refluxed under nitrogen for 2.5 hrs. Following the addition of para-toluenesulfonic acid monohydrate (11.9 g), the reaction mixture was heated at reflux for 48 hrs. The reaction was cooled and filtered and the filtrate was concentrated in vacuo to give a brown oil. The crude material was dissolved in dichloromethane and absorbed onto a column of Merck-60 flash silica gel. Elution with 20% ethyl acetate in hexane provided a brown solid which was triturated with diethyl ether to give the title product (2.1 g, 25.0%) as a white solid, m.p. 111-112° C.

1. temperaturethe reaction mixture was heated
2. temperatureat reflux for 48 hrs
3. temperatureThe reaction was cooled
4. filtrationfiltered
5. concentrationthe filtrate was concentrated in vacuo
6. customto give a brown oil
7. customabsorbed onto a column of Merck-60 flash silica gel
8. washElution with 20% ethyl acetate in hexane
9. customprovided a brown solid which
10. customwas triturated with diethyl ether