Butanal, oxime → 3-Butyl-isoxazole-4-carboxylic acid ethyl ester
Reaction equation
[CH:1](=[N:6][OH:7])[CH2:2][CH2:3][CH2:4][CH3:5].C(=NO)CCC.CN[C:16](NC)=[CH:17][C:18]([O:20][CH2:21][CH3:22])=[O:19]>>[CH2:21]([O:20][C:18]([C:17]1[C:1]([CH2:2][CH2:3][CH2:4][CH3:5])=[N:6][O:7][CH:16]=1)=[O:19])[CH3:22]Participants
4
Procedure
As described for example 1a except using valeraldehyde (12.4 mL, 116 mmol) instead of butyraldehyde, the penatnal oxime intermediate product (11.7 g, 99%) was obtained as a yellow solid and as a mixture of cis and trans isomers that was used directly without further purification. MS (EI): m/e=101.0 [M]+. Then as described for example 1b, except using (E and/or Z)-pentanal oxime (11.4 g, 113 mmol) instead of (E and/or Z)-butanal oxime, and using ethyl 3,3-dimethylaminoacrylate instead of ethyl (E)-3-(1-pyrrolidino)-2-butenoate, the title compound (13.6 g, 61%) was obtained as a yellow liquid after purification by chromatography (silica, 0 to 10% ethyl acetate in heptane). MS: m/e=198.1 [M+H]+.
Workup
- customwas used directly without further purification
Sources & evidence
- ORD record
- ord-6c24142aadf140559a94a96d82748361
- Source dataset
- uspto-grants-2013_01
- Patent number
- US08357703B2
Reaction notes
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