3-Pyridine aldoxime → 3-(4,5-Bis-trimethylsilanyl-isoxazol-3-yl)-pyridine

HRID 660142Notes

Reaction equation

[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]([CH:7]=[N:8][OH:9])[CH:2]=1.C(#[N+][O-])C1C=CC=NC=1.[CH3:19][Si:20]([CH3:28])([CH3:27])[C:21]#[C:22][Si:23]([CH3:26])([CH3:25])[CH3:24]>>[CH3:19][Si:20]([CH3:28])([CH3:27])[C:21]1[C:7]([C:3]2[CH:2]=[N:1][CH:6]=[CH:5][CH:4]=2)=[N:8][O:9][C:22]=1[Si:23]([CH3:26])([CH3:25])[CH3:24]

Participants

Reactant 3

HCID 6943-Pyridine aldoxime

HCID 84564Bis(trimethylsilyl)acetylene

HCID 12359258Nicotinonitrile oxide

Product 1

HCID 575480363-(4,5-Bis-trimethylsilanyl-isoxazol-3-yl)-pyridine

Procedure

Commercially available 3-pyridinealdoxime (61) is converted to its chlorohydroxyimino derivative (US 2004/0157900) which is converted to nicotinonitrile oxide (Tetrahedron, 61, 2005, 4363-4371) “in situ” and reacted with 1,2-bis-trimethylsilanyl-ethyne (Chem. Ber., 107, 1974, 3717-3722) to afford the 1,3-dipolar cycloaddition product 3-(4,5-bis-trimethylsilanyl-isoxazol-3-yl)-pyridine (62). Halogen-induced ipso desilylation resulted in the 4-bromo-5-trimethylsilanyl derivative (63). Subsequent desilylation with NH4OH (Chem. Ber., 112, 1979, 2829-2836) generates 3-(4-bromo-isoxazol-3-yl)-pyridine (64).

Sources & evidence

ORD record: ord-c012b85946934f368083d4020aab4fa0
Source dataset: uspto-grants-2011_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08084473B2

Reaction notes

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