Water → [1,2,4]Triazolo[1,5-a]pyridine-6-carbaldehyde

HRID 1432420Notes

Reaction equation

I[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([N:8]=[CH:9][N:10]=2)[CH:7]=1.C([Mg]Br)(C)C.CN([CH:19]=[O:20])C.O>C1COCC1>[N:10]1[CH:9]=[N:8][N:6]2[CH:7]=[C:2]([CH:19]=[O:20])[CH:3]=[CH:4][C:5]=12

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 6-iodo-[1,2,4]triazolo[1,5-a]pyridine (5.0 g, 20 mmol; prepared from 2-amino-5-iodopyridine (Aldrich-Sigma, St. Louis, Mo.) according to WO 01/62756) in anhydrous THF (300 mL) at 0° C. was slowly added a solution of isopropylmagnesium bromide in THF (1 M, 31 mL, 31 mmol). The resulting milky suspension was stirred at 0° C. After an hour, DMF (6 mL, 50 mmol) was added to the suspension at 0° C. and the suspension was allowed to warm up to room temperature and stirred for 4 additional hours. 100 mL of water was then added at room temperature and stirred for 1 hour. The resulting mixture was extracted with diethylether and washed with saturated Na2CO3. The extracts were dried over MgSO4 and concentrated. The residue was purified on a short silica gel cake with EtOAc to give [1,2,4]triazolo[1,5-a]pyridine-6-carbaldehyde as a light yellow solid (3 g, 100%). ESP+ m/e 148.0. 1H NMR (CDCl3, 300 MHz), δ 10.03 (s, 1H), 9.10 (s, 1H), 8.49 (s, 1H), 8.02 (d, 1H), 7.82 (d, 1H).

Workup

waitAfter an hour
temperatureto warm up to room temperature
stirringstirred for 4 additional hours
stirringstirred for 1 hour
extractionThe resulting mixture was extracted with diethylether
washwashed with saturated Na2CO3
dry with materialThe extracts were dried over MgSO4
concentrationconcentrated
customThe residue was purified on a short silica gel cake with EtOAc

Sources & evidence

ORD record: ord-75767285c1e64fb08f515509d96d0a94
Source dataset: uspto-grants-2009_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07612094B2

Reaction notes

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