Phthalimide → 2-((3-Chloropyrazin-2-yl)methyl)isoindoline-1,3-dione

HRID 1163260Notes

Reaction equation

HRID 1163260 reaction equation
[Cl:1][C:2]1[C:3]([CH2:8]O)=[N:4][CH:5]=[CH:6][N:7]=1.[C:10]1(=[O:20])[C:18]2[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=2)[C:12](=[O:19])[NH:11]1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CC(OC(/N=N/C(OC(C)C)=O)=O)C>C1COCC1>[Cl:1][C:2]1[C:3]([CH2:8][N:11]2[C:12](=[O:19])[C:13]3[C:18](=[CH:17][CH:16]=[CH:15][CH:14]=3)[C:10]2=[O:20])=[N:4][CH:5]=[CH:6][N:7]=1

Participants

6

Procedure

A solution of (3-chloropyrazin-2-yl)-methanol (47 g, 0.33 mol), isoindole-1,3-dione (58.3 g, 0.396 mol, 1.2 eq.), and triphenylphosphine (89.7 g, 0.396 mol, 1.2 eq.) in anhydrous THF (1.5 L) was charged with DIAD (80.2 g, 0.396 mol, 77.1 mL, 1.2 eq.) dropwise at rt, under N2, making sure the internal temperature did not surpass 40° C. The crude material was adsorbed onto silica gel, dry loaded, and purified by chromatography on silica gel [6″×6″ column, 2.75 kg silica gel, eluting with Hex:CH2Cl2 1:1→neat CH2Cl2→MeCN:CH2Cl2 2→10%.] Material was combined and concentrated in vacuo. Residue was dissolved as best as possible in hot CH2Cl2 (500 mL), after which i-PrOH was added and a white crystalline solid began to precipitate out of solution. Solid was filtered, washed with i-PrOH, and oven-dried to remove all traces of solvent, affording the title compound, as an off-white solid; 1H NMR (400 MHz, CDCl3) δ 5.10 (s, 1H), 7.75-7.80 (m, 2H), 7.89-7.94 (m, 2H), 8.26 (1H, d, J=2.45 Hz), 8.31 (1H, d, J=2.49 Hz); MS (ES+): m/z 274.21/276.19 (100/50) [MH+]; HPLC: tR=3.35 min (OpenLynx, nonpolar 7 min).

Workup

  1. customdid not surpass 40° C
  2. customdry loaded
  3. custompurified by chromatography on silica gel [6″×6″ column, 2.75 kg silica gel
  4. washeluting with Hex
  5. concentrationconcentrated in vacuo
  6. dissolutionResidue was dissolved as best as possible in hot CH2Cl2 (500 mL)
  7. additionafter which i-PrOH was added
  8. customto precipitate out of solution
  9. filtrationSolid was filtered
  10. washwashed with i-PrOH
  11. customoven-dried
  12. customto remove all traces of solvent

Sources & evidence

ORD record
ord-57a26c78c3cd4b69b8a1b1a4a99415b7
Source dataset
uspto-grants-2010_10
Patent number
US07820662B2

Reaction notes

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