Trifluoroacetic acid → 5-Cyano-3-methylpyridine-2-carboxylic acid

Reaction equation

C([O:5][C:6]([C:8]1[C:13]([CH3:14])=[CH:12][C:11]([C:15]#[N:16])=[CH:10][N:9]=1)=[O:7])(C)(C)C.COC1C=CC=C(OC)C=1.C(O)(C(F)(F)F)=O>C1(C)C=CC=CC=1>[C:15]([C:11]1[CH:12]=[C:13]([CH3:14])[C:8]([C:6]([OH:7])=[O:5])=[N:9][CH:10]=1)#[N:16]

Participants

Procedure

To a solution of 8.50 g (38.9 mmol) 5-cyano-3-methyl-pyridine-2-carboxylic acid tert-butyl ester in 51 ml (389 mmol) 1,3-dimethoxybenzene were added 85 ml TFA and stirred for 6.5 h. The reaction mixture was diluted with toluene and evaporated. The residue was taken up in toluene and evaporated (2×). The product was crystallized from TBME/hexanes to give the title compound as a white powder. HPLC: RtH1=2.314 min; ESIMS [M+Na]+=163; 1H-NMR (360 MHz, CDCl3): δ 8.77 (s, 1H), 8.07 (s, 1H), 2.87 (s, 3H).