4-Methyl-5-vinylthiazole → (E)-methyl 2-(cyclohexyloxy)-8-(4-methylthiazol-5-yl)oct-7-enoate

HRID 445404Notes

Reaction equation

[CH:1]1([O:7][CH:8]([CH2:13][CH2:14][CH2:15][CH2:16][CH:17]=[CH2:18])[C:9]([O:11][CH3:12])=[O:10])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[CH3:19][C:20]1[N:21]=[CH:22][S:23][C:24]=1C=C>C1(C)C=CC=CC=1>[CH:1]1([O:7][CH:8]([CH2:13][CH2:14][CH2:15][CH2:16]/[CH:17]=[CH:18]/[C:24]2[S:23][CH:22]=[N:21][C:20]=2[CH3:19])[C:9]([O:11][CH3:12])=[O:10])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of methyl 2-hydroxyoct-7-enoate (6.88 g, 0.040 mmol), dichloromethane (40 mL), 3,4-dihydro-2H-pyran (7.4 mL, 0.082 mol), and 6 drops of trifluoroacetic acid was stirred at room temperature overnight. The resulting mixture was concentrated in vacuo to yield methyl 2-(cyclohexyloxy)oct-7-enoate, which was used in the next step without further purification. A solution of methyl 2-(cyclohexyloxy)oct-7-enoate (500.0 mg, 1.95 mmol) dissolved in toluene (33 mL) containing 4-methyl-5-vinylthiazole (1.11 mL, 19.5 mmol) and Grubb's 2nd generation catalyst (166 mg, 0.195 mmol) was flushed with argon and heated in a sealed tube at 100° C. for 20 h. After cooling to room temperature, the solvent was removed in vacuo and the resulting residue was purified via flash silica gel chromatography (Analogix IF-280, SF25-115 g column, gradient 90:10-80:20 Heptane:EtOAc) to yield (E)-methyl 2-(cyclohexyloxy)-8-(4-methylthiazol-5-yl)oct-7-enoate. MS (ES+) 354 (M+1).

Workup

customwas used in the next step without further purification
customwas flushed with argon
temperatureAfter cooling to room temperature
customthe solvent was removed in vacuo
customthe resulting residue was purified via flash silica gel chromatography (Analogix IF-280

Sources & evidence

ORD record: ord-595cf626c9c040769cac23ef499480d1
Source dataset: uspto-grants-2013_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08476302B2

Reaction notes

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