Potassium Bromide → 5-methyl-1H-pyrrolo[3,2-b]pyridine

HRID 728769Notes

Reaction equation

HRID 728769 reaction equation
[CH3:1][C:2]1[N:7]=[C:6]([CH2:8][C:9]#N)[C:5]([N+:11]([O-])=O)=[CH:4][CH:3]=1.C(O)(=O)C.C(O)C.[K+].[Br-]>[Ni].CO.C(Cl)Cl>[CH3:1][C:2]1[N:7]=[C:6]2[CH:8]=[CH:9][NH:11][C:5]2=[CH:4][CH:3]=1

Participants

7

Reactant 3

HCID 253877Potassium BromideHCID 14822074(6-Methyl-3-nitropyridin-2-yl)acetonitrileHCID 18476134Acetic acid ethanol

Product 1

HCID 116296125-methyl-1H-pyrrolo[3,2-b]pyridine

Reagents, catalysts & solvents 3

HCID 935NickelCatalystHCID 887MethanolSolventHCID 6344DichloromethaneSolvent

Procedure

A mixture of (6-methyl-3-nitro-2-pyridyl)-acetonitrile (1.83 g, 10.3 mmol),Raney nickel (0.20 g) and acetic acid/ethanol (3:7) was shaken under an atmosphere of hydrogen for 4 hours. The resulting mixture was filtered, and the filtrate was evaporated under reduced pressure. The residual oil was partitioned between saturated sodium hydrogen carbonate (25 mL) and ethyl acetate (25 mL). The organic layer was removed, and the aqueous layer was extracted with ethyl acetate (2×25 mL). The organic extracts were combined, dried (MgSO4), and evaporated under reduced pressure to yield a yellow solid. Column chromatography of this solid using silica gel (approx 50 g) and elution with 5% methanol in methylene chloride yielded Compound 7k (0.32 g, 2.4 mmol, 24%) as a tan solid: mp, 200°-202° C.; IR (KBr) 1610, 1570, 1465, 1445, 1405, 1290 cm-1 ; 1H NMR (DMSO-d6) δ 11.15 (br s, 1H), 7.65 (d,J=8.5 Hz, 1H), 7.54 (m, 1H), 6.95 (d, J=8.5 Hz, 1H), 6.45 (br m, 1H), 2.51 (s, 3H); 13 C NMR (DMSO-d6) 50.0, 145.7, 128.5, 126.6, 118.7, 116.0, 101.1, 24.2; Anal. calc'd for C8H8N2 ; C, 72.70; H, 6:10; N, 21.20; found: C, 72.22; H, 6.19; N, 21.25.

Workup

  1. filtrationThe resulting mixture was filtered
  2. customthe filtrate was evaporated under reduced pressure
  3. customThe residual oil was partitioned between saturated sodium hydrogen carbonate (25 mL) and ethyl acetate (25 mL)
  4. customThe organic layer was removed
  5. extractionthe aqueous layer was extracted with ethyl acetate (2×25 mL)
  6. dry with materialdried (MgSO4)
  7. customevaporated under reduced pressure
  8. customto yield a yellow solid
  9. custommp, 200°-202° C.

Sources & evidence

ORD record
ord-da0de26fa4c2406aa2a95f90a54671a1
Source dataset
uspto-grants-1991_09
Patent number
US05051412

Reaction notes

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