Diethyl Carbonate → Ethyl 2-oxocyclohexanecarboxylate

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Reaction Steps

The compounds of this invention may be prepared using methods known to those skilled in the art, or the novel methods of this invention. Specifically, the compounds of this invention with Formula I, II or III can be prepared as illustrated by the exemplary reaction in Scheme 1. Reaction of cyclohexanone with diethyl carbonate in THF in the presence of NaH produced ethyl 2-oxocyclohexanecarboxy late. Reaction of ethyl 2-oxocyclohexanecarboxylate with urea at 175-185° C. produced 5,6,7,8-tetrahydroquinazoline-2,4(1H, 3H )-dione. Reaction of 5,6,7,8-tetrahydroquinazoline-2,4(1H, 3H )-dione with hexamethyldisilazane (HMDS) in toluene in the presence of concentrated sulfuric acid, produced the intermediate 2,4-di(trimethylsilyloxy)-5,6,7,8-tetrahydroquinazol. Reaction of 2,4-di(trimethylsilyloxy)-5,6,7,8-tetrahydroquinazoline with methyl 3-(bromomethyl)benzoate in DMF , followed by treatment with 1,4-dioxane and methanol, produced 1-(3-methoxycarbonylbenzyl)-5,6,7,8-tetrahydroquinazoline-2,4(1H,3H )-dione. Treatment of the ester with NaOH in water-methanol produced 1-(3-carboxybenzyl)-5,6,7,8-tetrahydroquinazoline-2,4(1H,3H)-dione. Coupling of the acid with a substituted amine, such as 1-(pyrimidin-2-yl)piperazine, in the presence of coupling agents, such as 2-(7-aza-1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HATU) and N,N-diisopropylethylamine (DIPEA) in DMF, produced the targeted compound 1-(3-(4-(pyrimidin-2-yl)piperazine-1-carbonyl)benzyl)-5,6,7,8-tetrahydroquinazoline-2,4(1H, 3H)-dione.

Provenance & Evidence