Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → 5,6-Diphenyl-2-(5-hydroxy-1-pentyn-1-yl)pyrazine
Reaction equation
[C:1]1([C:7]2[N:8]=[CH:9][C:10]([C:19]#[C:20][CH2:21][CH2:22][CH2:23][O:24]C3CCCCO3)=[N:11][C:12]=2[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>CO>[C:1]1([C:7]2[N:8]=[CH:9][C:10]([C:19]#[C:20][CH2:21][CH2:22][CH2:23][OH:24])=[N:11][C:12]=2[C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1Participants
4
Procedure
To a solution of 1.79 g of 5,6-diphenyl-2-[5-(2-tetrahydropyranyloxy)-1-pentyn-1-yl]pyrazine in methanol, 1.13 g of pyridinium p-toluenesulfonate was added and the mixture was heated at reflux for 30 minutes. The reaction solution was poured into ice water while stirring, extracted with ethyl acetate and then dried over anhydrous magnesium sulfate. After the solvent was evaporated under reduced pressure, the resulting crystal was recrystallized from diisopropyl ether to obtain 1.00 g of the desired compound as a yellow crystal having a melting point of 88 to 90° C.