Phosphorus oxide (P4O10) → HCID 59396590, compound

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][CH2:10][NH:11][C:12]([CH:14]2[CH2:19][CH2:18][CH2:17][CH2:16][CH2:15]2)=O)=[CH:5][CH:4]=1.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.P(Cl)(Cl)(Cl)=O>C1(C)C=CC=CC=1>[CH:14]1([C:12]2[C:7]3[C:6](=[CH:5][CH:4]=[C:3]([O:2][CH3:1])[CH:8]=3)[CH2:9][CH2:10][N:11]=2)[CH2:19][CH2:18][CH2:17][CH2:16][CH2:15]1

Participants

Procedure

N-[2-(4-methoxyphenyl)ethyl]cyclohexanecarboxamide (5.56 g) was dissolved in toluene (120 mL), and diphosphorus pentoxide (3.0 g) and phosphorus oxychloride (6.0 mL) were sequentially added thereto, followed by stirring under heating at reflux for 5.5 hours. The reaction mixture was left to cool and then the solvent was evaporated. An aqueous 8 M potassium hydroxide solution, water and chloroform were added to the resulting residue to completely dissolve the insoluble materials to achieve a pH of around pH 8, followed by extraction with chloroform. The extract was washed with saturated brine, and then dried over magnesium sulfate. The solvent was evaporated and the resulting residue was purified by silica gel column chromatography (chloroform-MeOH) to obtain 1-cyclohexyl-7-methoxy-3,4-dihydroisoquinoline (1.87 g).