Sodium Hydroxide → 4-(((1R,3S)-3-((tert-butoxycarbonyl)amino)-2,2,3-trimethylcyclopentyl)amino)-3-carbamoylpyrrolo[1,2-b]pyridazine-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl 4-((1R,3S)-3-(tert-butoxycarbonylamino)-2,2,3-trimethylcyclopentylamino)-3-carbamoylpyrrolo[1,2-b]pyridazine-6-carboxylate (10.62 g, 22.42 mmol) and 1 N NaOH (120 mL) in THF (100 mL) and MeOH (100 mL) was heated to 60° C. for 16 hrs. and then the reaction mixture was added 120 ml of 1 N NaOH solution and heated to 70° C. for 8 hrs. The reaction mixture was added 120 ml of 1 N NaOH solution and heated to 70° C. for 8 hrs which was concentrated to remove THF and MeOH. The aqueous layer was acidified with conc. HCl solution until pH about 4 at 0-5° C. The solid was collected to give 4-(((1R,3S)-3-((tert-butoxycarbonyl)amino)-2,2,3-trimethylcyclopentyl)amino)-3-carbamoylpyrrolo[1,2-b]pyridazine-6-carboxylic acid (11.2 g, 76% yield). HPLC retention time=3.020 min., LC/MS (M+H)+=446.3.

Provenance & Evidence