3-Butyl-5-methyl-isoxazole-4-carbaldehyde → 3-[(E)-2-(3-Butyl-5-methyl-isoxazol-4-yl)-vinyl]-isoxazole-5-carboxylic acid ethyl ester

HRID 1920895Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[O:10][N:9]=[C:8]([C:11](C2C=CC=CC=2)(C2C=CC=CC=2)[PH2]=O)[CH:7]=1)=[O:5])[CH3:2].[Li]CCCC.[CH2:31]([C:35]1[C:39]([CH:40]=O)=[C:38]([CH3:42])[O:37][N:36]=1)[CH2:32][CH2:33][CH3:34]>C1COCC1>[CH2:1]([O:3][C:4]([C:6]1[O:10][N:9]=[C:8](/[CH:11]=[CH:40]/[C:39]2[C:35]([CH2:31][CH2:32][CH2:33][CH3:34])=[N:36][O:37][C:38]=2[CH3:42])[CH:7]=1)=[O:5])[CH3:2]

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 3-(diphenyl-phosphinoylmethyl)-isoxazole-5-carboxylic acid ethyl ester (410 mg, 1.2 mmol) in THF (10 mL) at −78° C. was added BuLi (1.6 M in hexanes, 0.79 mL, 1.3 mmol) and the mixture warmed up to 0° C. over 1 h and a solution of 3-butyl-5-methyl-isoxazole-4-carbaldehyde (193 mg, 1.2 mmol) in THF (5 mL) added and stirred for 2 h. The mixture was extracted with ethyl acetate and the combined organic layers were then washed with water and brine and then dried over sodium sulfate, filtered and evaporated. Purification by chromatography (silica, heptane:ethyl acetate=100:0 to 7:3) afforded the title compound (75 mg, 21%) as a colourless oil. MS: m/e=305.2 [M+H]+.

Workup

extractionThe mixture was extracted with ethyl acetate
washthe combined organic layers were then washed with water and brine
dry with materialdried over sodium sulfate
filtrationfiltered
customevaporated
customPurification by chromatography (silica, heptane:ethyl acetate=100:0 to 7:3)

Sources & evidence

ORD record: ord-ea47ee823a90441bb242672ccc80d1e0
Source dataset: uspto-grants-2012_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08173652B2

Reaction notes

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