Diisopropylethylamine → GSK PERK Inhibitor

Participants

Reaction Steps

To a suspension of 5-(2,3-dihydro-1H-indol-5-yl)-7-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine 2HCl (1.80 g, 5.32 mmol, 1 equiv) and HATU (2.23 g, 5.85 mmol, 1.1 equiv) in 18 mL of DMF was added DIEA (2.97 mL, 17.03 mmol, 3.2 equiv) in one portion. The mixture turned into a light brownish clear solution, and was chilled in an ice bath. To this stirred solution was added [3-fluoro-5-(trifluoromethyl)phenyl]acetic acid portionwise (1.18, 5.32 mmol, 1 equiv) as solids over a period of 1 h. After completion of acid addition, the cooling bath was removed. After 30 min, the mixture became a milky texture. After another 1.5 h, the mixture was poured into to 200 mL of ice water to give a suspension, which was filtered. The cake was washed with water, and ether, and then dried under house vacuum at room temperature for 18 hours. This material was dissolved in 10% MeOH in DCM, and was absorbed onto 3 dryload silica gel cartridges (in about equal portions). Purification was done on Analogix SF40-80 g silica gel cartridge using gradient elution of 1% A to 60% A in CHCl3 (A was a mixture of 3200/800/80 CHCl3/MeOH/NH4OH). The desired product eluted from 23-28% A. The collected fractions were combined and concentrated in vacuo to afford the product as a white residue. The front running impure fractions (21-22% A) were combined and the residue (LCMS showed presence of a non-polar impurity) was dissolved in 10% MeOH in DCM and absorbed onto a dryload cartridge. Purification was done on an Analogix SF25-60 g silica gel cartridge using gradient elution of 1% A in EtOAc 75% A (A was a mixture of 20% MeOH in EtOAc). The desired product eluted from 59-75% A. The combined fractions were conc in vacuo to afford additional product, which was combined with the above pure sample and dissolved in 70 mL of 10% MeOH in DCM, followed by filtration. The filtrate was conc in vacuo. The residue was taken up in 40 mL of 10% MeOH in DCM. The mixture was conc n vacuo to about 10 mL. The suspension was diluted with 20 mL of MTBE, and then concentrated in vacuo to half volume. The mixture was again diluted with 20 mL of MTBE. The resulting suspension was filtered. The cake was washed with MTBE (3×15 mL). The solids were then dried under vacuum at 65° C. for 48 h to afford 5-(1-{[3-fluoro-5-(trifluoromethyl)phenyl]acetyl}-2,3-dihydro-1H-indol-5-yl)-7-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine (2.026 g) as white solids. LC-MS (ES) m/z=470 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm 3.26 (t, J=8.3 Hz, 2H), 3.73 (s, 3H), 4.07 (s, 2H), 4.27 (t, J=8.5 Hz, 2H), 5.91-6.26 (br s, 1.4; H), 7.23 (d, J=8.3 Hz, 1H), 7.26 (s, 1H), 7.33 (s, 1H), 7.51 (d, J=9.6 Hz, 1H), 7.56-7.64 (m, 2H), 8.10 (d, J=8.3 Hz, 1H), 8.15 (s, 1H).

Provenance & Evidence