Реакция #44820

Уравнение реакции

isothiocyanate

thiourea

thiophosgene

dicyclohexylcarbodiimide

NaHCO3

→

2-aminobenzimidazole

Растворители

THF

dichloromethane

Условия реакции

Обработка

1. 1
   Другоеprepared
2. 2
   Другоеevaporated to dryness
3. 3
   ДругоеThe resulting thiourea was then purified by e.g. column chromatography
4. 4
   Другоеreacted further as crude material
5. 5
   workup.STIRRINGstirred
6. 6
   Температураat reflux temperature overnight
7. 7
   Экстракцияthe solution extracted with EtOAc
8. 8
   СушкаThe combined organic phases were dried (MgSO4)
9. 9
   Фильтрацияfiltered
10. 10
    Концентрированиеconcentrated in vacuo

Методика

A mixture of an isothiocyanate (prepared by reacting the corresponding amine with thiophosgene) and a suitably substituted phenylenediamine in dry dichloromethane was stirred at rt overnight and evaporated to dryness. The resulting thiourea was then purified by e.g. column chromatography or reacted further as crude material. Thus, the thiourea was dissolved in THF, added a coupling reagent such as dicyclohexylcarbodiimide (DCC), and stirred at reflux temperature overnight. Aqueous NaHCO3 was added and the solution extracted with EtOAc. The combined organic phases were dried (MgSO4), filtered and concentrated in vacuo to give the crude 2-aminobenzimidazole which was subsequently purified by column chromatography or preparative LCMS.

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