Ethyl 2-iodo-3-methylbenzoate → Ethyl 3-methyl-2-(oxazol-2-yl)benzoate

HRID 64209Notes

Reaction equation

I[C:2]1[C:12]([CH3:13])=[CH:11][CH:10]=[CH:9][C:3]=1[C:4]([O:6][CH2:7][CH3:8])=[O:5].C([Sn](CCCC)(CCCC)[C:19]1[O:20][CH:21]=[CH:22][N:23]=1)CCC>COCCOC.[Cu]I.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:13][C:12]1[C:2]([C:19]2[O:20][CH:21]=[CH:22][N:23]=2)=[C:3]([CH:9]=[CH:10][CH:11]=1)[C:4]([O:6][CH2:7][CH3:8])=[O:5]

Participants

Conditions

Temperature: 150 °C

Procedure

In a microwave vial was dissolved ethyl 2-iodo-3-methylbenzoate (627 mg, 2.16 mmol) and 2-(tributylstannyl)oxazole (0.54 mL, 0.07 mmol) in DME (2.59 mL). The solution was degassed with N2 for 5 minutes then CuI (21 mg, 0.11 mmol) and Pd(PPh3)4 (125 mg, 0.11 mmol) were added. The reaction was purged with N2 and heated at 150° C. for 1 h. The reaction was cooled to room temperature, filtered through a pad of Celite and purified via silica gel chromatography (0-40% EtOAc in hexanes) to give the title compound of step A (333 mg, 67%). MS (ESI) mass calcd. for C13H13NO3, 231.1. m/z found 232.1 [M+H]+. 1H NMR (500 MHz, Chloroform-d) δ 7.89-7.82 (m, 1H), 7.79 (d, J=0.8 Hz, 1H), 7.48-7.43 (m, 2H), 7.30 (d, J=0.9 Hz, 1H), 4.17 (q, J=7.1 Hz, 2H), 2.27 (s, 3H), 1.18 (t, J=7.1 Hz, 3H).

Workup

customThe solution was degassed with N2 for 5 minutes
customThe reaction was purged with N2
temperatureThe reaction was cooled to room temperature
filtrationfiltered through a pad of Celite
custompurified via silica gel chromatography (0-40% EtOAc in hexanes)

Sources & evidence

ORD record: ord-faf74774f08945bba4b7a7208151c515
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09447117B2

Reaction notes

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