Acetic Acid → 3-(Tert-butylamino)-2-(5-(phenylethynyl)thiophen-2-yl)imidazo[1,2-a]pyrazine-8-carboxylic acid

Participants

Reaction Steps

A solution of 200 mg (0.47 mmol) of 3-(tert-butylamino)-2-(5-(phenylethynyl)-thiophen-2-yl)imidazo[1,2-a]pyrazine-8-carboxylic acid methyl ester (Example 106) in a mixture of MeOH (5 ml) and MeCN (5.5 ml) was combined with 5 ml (0.51 mmol) of a 0.1M aq. NaOH solution and stirred at RT for 1 h. The reaction mixture was then combined with 26 μl of a 5 N aq. acetic acid solution. The solvents were then largely removed by distillation under a vacuum. The residual aq. phase was repeatedly extracted with EA. The combined organic phases were dried over MgSO4, filtered and evaporated under a vacuum. 87 mg (0.21 mmol, 44%) of 3-(tert-butylamino)-2-(5-(phenylethynyl)thiophen-2-yl)imidazo[1,2-a]pyrazine-8-carboxylic acid were obtained by crystallisation of the group from DCM/hexane (1:2).

Provenance & Evidence