Benzyl ethyl hydrogen phosphate

Benzyl 8-quinolyl hydrogen phosphate heated 5 hrs. at 70° with ethanol and CuClg in anhydrous pyridine benzyl ethyl phosphate. Y 90% as the Ba-salt. F. e., also phosphoric acid monoesters, and sym. diphosphoric acid diesters with cupric acetate, s. K. Nagasawa and H. Yoshidome, Chem. Pharm. Bull. 20, 1840 (1972) s. a. H. Takaku, Y. Shimada, and K. Aral, Bull. Chem. Soc. Japan 47, 779 (1974). 

C, and the excess hydride killed by the addition of 1.0 mL EtOAc, followed by 2.3 mL H20. The reaction mixture was filtered free of solids under a N2 atmosphere, washed with THF, and the filtrate and washings combined and stripped of solvent under vacuum. The residue was distilled in a KugelRohr apparatus and the solid distillate recrystallized from /hexane to give 0.24 g (52%) 3-[2-(diethylamino)ethyl]-4-indolol (4-HO-DET) as white crystals with a mp of 103-104 °C. The product discolored quickly in the presence of air, and was best stored under an inert atmosphere at -30 °C. Conversion to the phosphate ester was achieved by reaction of the sodium salt of 3-[2-(diethylamino)ethyl]-4-indolol with dibenzylchlorophosphonate, followed by the reductive removal of the benzyl groups with catalytic hydrogenation, as described for psilocybin. 

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