Carbon tetrabromide → HCID 59231920, compound

Participants

Reaction Steps

To a solution of 3-(4-Amino-5-bromopyrrolo[2,1-f][1,2,4]triazin-7-yl)-propan-1-ol (1.20 g, 4.43 mmol) in anhydrous THF (22 mL) at 0° C. was added carbon tetrabromide (1.62 g, 4.87 mmol, 1.1 eq) and triphenylphosphine (1.16 g, 4.43 mmol, 1.0 eq). After 5 minutes the ice bath was removed and the reaction mixture was stirred at RT for 1 hour. Then another 0.1 equivalents of both carbon tetrabromide (0.15 g, 0.44 mmol) and triphenylphosphine (0.12 g, 0.44 mmol) were added. The reaction was stirred another hour at ambient temperature before it was filtered to remove some solid which was rinsed with some THF. The combined filtrate and rinse were concentrated at reduced pressure to give a crude product which was purified by MPLC on 120 g of silica gel eluted with a gradient from 0-100% EtOAc in hexane to give 950 mg (64.2%) of desired product as a white solid after evaporation of best fractions which eluted from 55-65% EtOAc. 1H-NMR (DMSO-d6) 7.84 (s, 1H), 6.65 (s, 1H), 3.54 (t, 2H, J=6.4), 2.94 (t, 2H, J=6.4), and 2.16 (q, 2H, J=6.4); MS LC-MS [M+H]+=333.3/335.1/337.1, RT=2.77 min. Evidence showed in the NMR and the LC-MS for about 16% contamination with 5,6-dibromo-7-(3-bromopropyl)pyrrolo[2,1-f][1,2,4]triazin-4-amine which came from an analogous contaminant (3-(4-Amino-5,6-dibromopyrrolo[2,1-f][1,2,4]triazin-7-yl)-propan-1-ol) in the starting material. Products that came from this contaminant were removed by chromatography of the product of step 5 below.

Provenance & Evidence