Phosphorus oxide (P4O10) → 1-(4-Chlorophenyl)-5-methyl-3,4-dihydroisoquinoline

Participants

Reaction Steps

Thirty-six (36) grams of 1-(4-chlorobenzoylamino)-2-(2-methylphenyl)ethane was dissolved in 180 ml of xylene and 100 ml of phosphorus oxychloride. While the solution was heated with stirring, 80 g of phosphorus pentoxide was added gradually, and the mixture was heated under reflux. The reaction mixture was poured into ice water. The aqueous layer was separated, and made weakly alkaline with ammonia water. Recrystallization of the precipitated oily product from n-hexane afforded 31 g of 1-(4-chlorophenyl)-5-methyl-3,4-dihydroisoquinoline as colorless prisms having a melting point of 66° to 67° C.

Provenance & Evidence