Sodium Hydroxide → 1-(5-Chloroindolin-1-yl)-thiourea

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Reaction Steps

1-amino-5-chlorindoline was reacted with benzoyl isothiocyanate in boiling tetrahydrofuran. Saponification of the resulting product with dilute aqueous sodium hydroxide under reflux for 15 minutes gave 1-(5-chloroindolin-1-yl)-thiourea (M.Pt. 199° - 200° from ethyl acetate/petroleum ether). This thiourea was heated in boiling methanol in the presence of methyliodide for 1 hour to give 1-(5-chloroindolin-1-yl)-2-methylisothiourea hydroiodide. The base was liberated with aqueous sodium hydroxide. Reaction of the base with 2N ethanolic hydrogen chloride yielded 1-(5-chlorindolin-1-yl)-2-methylisothiourea hydrochloride (M.Pt. 178° - 179° from ethanol/ether).

Provenance & Evidence