Propyltriphenylphosphonium bromide → 4-(5-But-1-enyl-imidazol-1-yl)-3,3-dimethyl-isochroman-1-one
Reaction equation
[Br-].[CH2:2]([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[CH2:3][CH3:4].[CH3:24][C:25]1([CH3:43])[CH:34]([N:35]2[C:39]([CH:40]=O)=[CH:38][N:37]=[CH:36]2)[C:33]2[C:28](=[CH:29][CH:30]=[CH:31][CH:32]=2)[C:27](=[O:42])[O:26]1>C1COCC1>[CH:40]([C:39]1[N:35]([CH:34]2[C:33]3[C:28](=[CH:29][CH:30]=[CH:31][CH:32]=3)[C:27](=[O:42])[O:26][C:25]2([CH3:43])[CH3:24])[CH:36]=[N:37][CH:38]=1)=[CH:2][CH2:3][CH3:4]Participants
4
Procedure
To a solution of propyltriphenylphosphonium bromide (0.157 g, 0.41 mmol) in THF (1 mL) at −78° C. is added sodium hexamethyldisilylamide (1M in THF, 0.44 mL, 0.44 mmol) and the mixture is allowed to warm to ambient temperature over 10 min. This solution is cooled to −20° C. and 3-(3,3-dimethyl-1-oxo-isochroman-4-yl)-3H-imidazole-4-carbaldehyde (0.10 g, 0.37 mmol) in THF (0.2 mL) is added. The cooling bath is removed and the mixture is stirred at ambient temperature overnight, then filtered. The filtrate is concentrated in vacuo to give the crude 4-(5-but-1-enyl-imidazol-1-yl)-3,3-dimethyl-isochroman-1-one which is used in the next step without further purification; MS (ESI) m/z 297.1 (M+H).