Sodium Hydroxide → HCID 178504928, compound

Participants

Reaction Steps

3.82 g of 2-chloroimidazoline hydrogen sulfate (see Example 6A) was treated with 50 ml of 1M NaOH solution and immediately extracted with CH2Cl2 (3×20 ml). The extracts were dried (K2CO3) and the solution decanted. 10 ml of isopropanol was added and the CH2Cl2 was removed at reduced pressure. The resultant isopropanol solution was added to a refluxing solution of the N-methanesulfonyl-6-aminoindole (2.02 g, 9.61 mmol) in isopropanol (10 mmol). The mixture was refluxed for 3 hr, cooled, and concentrated under vacuum. A portion (800 mg) of the crude product was dissolved in MeOH:H2O (5:1) then 10 g of silica gel was added. The mixture was dried under vacuum and the resulting powder was applied to a silica gel column and eluted with ethyl acetate:MeOH:iPrNH2 (93:5:2) (iPr=isopropyl). The white solid obtained was suspended in MeOH (4 ml) and treated with 3 ml of 1.0M HCl/ether. The solid dissolved then a precipitate formed which was filtered off after chilling the mixture in an ice bath. 590 mg of N-methanesulfonyl-6-(imidazolidin-2-ylideneamino)indole hydrochloride were obtained (mp 167.6-170.6° C.).

Provenance & Evidence