Cortisol → N,N'-Dicyclohexylurea

To a solution of hydrocortisone (10 g, 0.028 mole) and N,N-(3'-oxapentamethylene)succinamic acid (5.16 g, 0.028 mole) in 50 ml pyridine was added dicyclohexylcarbodiimide (5.67 g, 0.028 mole). After the reaction was stirred 10 minutes, 50 ml CH2Cl2 was added to it to keep the suspension, which had formed, sufficiently fluid for stirring. The reaction was stirred overnight then filtered to give a residue of dicyclohexylurea which weighed 4.51 g (83% yield) and a filtrate which was concentrated in vacuo to a light off-white foam. The foam was in turn triturated (25 ml CH2Cl2, 3 hours) then filtered to give a residue weighing 6.4 g and a filtrate which was concentrated in vacuo to 10.4 g. The 10.4 g was in turn triturated (100 ml MeOH, overnight) then filtered to give a residue weighing 4.3 g. The residue was recrystallized from 200 ml EtOH to give a fine white crystalline product, which, after it was dried in vacuo (35° C., 2 hours), weighed 3.4 g: mp 223°-225° C.; NMR (DMSO-d6) δ5.55 (s, 1, O=C--CH=), 5.33 (s, 1, OH), 4.93 (ABq, 2, JAB=19 Hz, ΔνAB =19 Hz, O=C--CH2 --O), 4.28 (m, 2, CHOH), 3.50 (m, 8, N(CH2CH2)2O), 2.62 (s, 4, OCCH2CH2CO), 1.38 (s, 3, C--CH3), 0.78 (s, 3, C--CH3), 2.9-0.8 (m, 17, CH, CH2- ; IR (KBr) 3500-3300 cm-1 (s) (OH), 1710, 1660 and 1610 cm-1 (s) (C=O); [α]25D=+131, (C=0.5, dioxane); TLC (silica gel), 10% MeOH/Et2O) Rf 0.29.