Formic Acid → HCID 59456071, compound

Participants

Reaction Steps

To a solution of formic acid (5 μL, 0.13 mmol) in dry DMF (0.3 mL) was added TBTU (34.7 mg, 0.108 mmol) followed with triethylamine (50.2 μl, 0.360 mmol). This mixture was stirred at room temperature for about 10 min before adding N-[1-{[3-(aminomethyl)phenyl]methyl}-4-(methyloxy)-1H-indazol-3-yl]-5-chloro-2-thiophenesulfonamide hydrochloride (for a preparation see Intermediate 4) (45 mg, 0.09 mmol). The resultant pale yellow mixture was stirred at room temperature overnight. LCMS showed very little reaction, so more acid (˜0.25 mL), followed with TBTU (˜30 mg) were added. This addition was repeated 3 more times over 20 h until by LCMS analysis, there was more product than SM. The reaction mixture was partitioned between ethylacetate (2 mL) and saturated sodium bicarbonate solution (2 mL). The aqueous was extracted with ethyl acetate (×2). The combined organic solutions were washed with water, brine, dried (Na2SO4) and concentrated in vacuo to leave a pale oil which crystallised on standing. This was dissolved in 1:1 MeOH:DMSO (1 mL) and purified by Mass Directed AutoPrep on supelcosil ABZ+Plus column eluting with a gradient of MeCN-Water (95:5+0.05% Formic acid)-Water (+0.1% Formic acid). The solvent was evaporated in vacuo to give the title compound (15.9 mg, 36%) as a pale yellow powder: LCMS (System A) RT=1.02 min, ES+ve m/z 491/493 (M+H)+.

Provenance & Evidence