Glycine → Glycine, N-cyclohexyl-

Participants

Reaction Steps

Similar equipment and procedure as described in Example 1 were employed. 75.5 grams glycine (1.01 moles, Aldrich, 99+%), 118.4 grams cyclohexanone (1.21 moles, Aldrich 99.8%), 300 ml glacial acetic acid and 11.2 grams of Pd (5%)/C were used. The reaction was carried out in a 600 ml Parr reactor under 1000 psig (7000 kPa) hydrogen pressure at 75° C. No noticeable hydrogen uptake was noticed after 1.5 days, and the reaction was carried out for 4.5 days. The reactor was opened after cooling to room temperature. The solid catalyst was filtered by suction. The filtrate was evaporated to remove the acetic acid and the excess cyclohexanone. A viscous crude product (brown) remained which started to crystallize upon cooling to room temperature. The crude product was stirred into excess ether whereby a white solid precipitated out. The solid was filtered, washed with ether and dried. The solid was redissolved in a very small amount of acetic acid and recrystallized by adding an appropriate amount of ether. 144.5 grams of white crystals were recovered (91% yield based on glycine). Elemental analysis:calculated: C:61.12; H:9.62; N:8.91; 0:20.36; found:C:60.96; H:9.75; N:8.88; 0:20.41.

Provenance & Evidence