Water → 4-[1,3 bis(cyclohexylmethyl)-1,2,3,6-tetrahydro-2,6-dioxo-9H-purin-8-yl]benzoic acid

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Reaction Steps

The title compound was prepared from 1,3-bis(cyclohexylmethyl)-5,6-aminouracil by the method of J. Perutmattam, Syn. Commun. 1989, 19:3367-3370. 1,3-Bis(cyclohexylmethyl)-5,6-diaminouracil was freshly prepared by shaking a mixture of 6-amino-1,3-bis(cyclohexylmethyl)-5-nitrosouracil (from step (c) example 1, 2.00 g, 5.74 mmol) in methanol (250 mL)-water (25 mL) with 10% palladium on carbon (0.20 g) under hydrogen (40 psi) on a Parr shaker for 2 h. The catalyst was filtered off (Celite) and the colorless filtrate was concentrated to 50 mL. 4-Carboxybenzaldehyde (Aldrich, 860 mg, 5.73 mmol) was added to this solution of 1,3-bis(cyclohexylmethyl)-5,6-diaminouracil. The resulting yellow mixture was concentrated and the residual yellow solid dried by evaporation of several portions of absolute ethanol. The yellow powder (Schiff base) was then stirred in dimethoxyethane (80 mL) with iodine (1.6 g, 6.30 mequiv) at 60° C. (oil bath) for 24 h. A saturated aqueous solution of sodium thiosulfate (~15 mL) was added to the warm reaction mixture until complete decolorization of iodine resulted. The pale yellow precipitate was filtered off, washed with water, and dried at 0.5 Torr to give 4-[1,3 bis(cyclohexylmethyl)-1,2,3,6-tetrahydro-2,6-dioxo-9H-purin-8-yl]benzoic acid as a pale yellow powder (2.13 g, 80%), m.p. >300° C.; 1 H-NMR (DMSO-d6) consistent with structure.

Provenance & Evidence