5-[(3-Phenylmethoxy-4-methoxyphenyl)methylene]-2,4-imidazolidinedione → (RS)-5-[[4-Methoxy-3-(phenylmethoxy)phenyl]methyl]-2,4-imidazolidinedione

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Reaction Steps

A solution of 16.20 g (0.05 mole) of the benzylidene hydantoin from Example 4 in 100 mL of methanol and 25.0 g (0.055 mole) of 20% tetramethylammonium hydroxide-in-methanol is reduced with hydrogen and Raney nickel catalyst. After the theoretical uptake of hydrogen the mixture is filtered and acetic acid (ca 5 mL) and then water is added until just turbid. The first crop of solid is filtered. This is starting material. An additional 2 L of water is added to precipitate the product as crop 2; wt 7.60 g (47% yield). Recrystallization from methanol gives pure product; mp 155°-157° C.

Provenance & Evidence