Phenylephrine Impurity 51 Phenylephrine USP RC F (4R)-1,2,3,4-Tetrahydro-2-methyl-4,8-isoquinolinediol Hydrochloride Hydrate DISCONTINUED. Please see T293580. Phenylephrine Impurity 6 Phenylephrine Related Compound F ((R)-2-Methyl-1,2,3,4-tetrahydroisoquinoline-4,8-diol hydrochlorid (1533261) 4,8-Isoquinolinediol, 1,2,3,4-tetrahydro-2-methyl-, hydrochloride, hydrate (1:1:1), (4R)- Phenylephrine Related Compound F as Hydrochloride Monohydrate Phenylephrine USP Related Compound F as Hydrochloride Monohydrate