Boron Trichloride → HCID 9878436, compound

HRID 431956Notes

Reaction equation

[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[C:7]1[N:11]=[C:10]([C:12]2[CH:17]=[C:16]([C:18]#[N:19])[CH:15]=[C:14]([O:20]CC=C)[CH:13]=2)[O:9][N:8]=1.B(Cl)(Cl)Cl>[I-].C([N+](CCCC)(CCCC)CCCC)CCC.ClCCl>[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[C:7]1[N:11]=[C:10]([C:12]2[CH:13]=[C:14]([OH:20])[CH:15]=[C:16]([C:18]#[N:19])[CH:17]=2)[O:9][N:8]=1

Participants

Conditions

Temperature: -78 °C

Procedure

A mixture of 3-(2-pyridyl)-5-(3-allyloxy-5-cyanophenyl)-1,2,4-oxadiazole (1.0 g, 3.4 mmol) and tetrabutylammonium iodide (1.4 g, 3.8 mmol) in dichloromethane (18 mL) at −78° C., under argon, was treated with a solution of 1M boron trichloride in dichloromethane (22 mL, 22 mmol). After 5 minutes at −78° C. the reaction mixture was stirred at ambient temperature for 1 hour. The reaction was then quenched with ice water and stirred for 30 minutes. The mixture was then washed with saturated sodium bicarbonate and extracted with dichloromethane. The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated. Silica gel chromatography using a gradient of 10% ethyl acetate in hexanes to 80% ethyl acetate in hexanes afforded 460 mg (51%) of 3-(2-pyridyl)-5-(3-cyano-5-hydroxyphenyl)-1,2,4-oxadiazole: 1H NMR (CDCl3/MeOD): δ-8.81 (d, 1H), 8.23 (d, 1H), 8.01 (s, 1H), 7.95 (m, 1H), 7.92 (m, 1H), 7.54 (m, 1H), 7.35 (m, 2H).

Workup

customThe reaction was then quenched with ice water
stirringstirred for 30 minutes
washThe mixture was then washed with saturated sodium bicarbonate
extractionextracted with dichloromethane
dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-91d8552016c549059c47180df78f6fef
Source dataset: uspto-grants-2003_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06660753B2

Reaction notes

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