p-Toluenesulfonic acid monohydrate → HCID 178497017, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 71 mg (0.171 mmol) of 2-(4-benzyloxy-benzoyl)-4-cyclohexyl-butyric acid ethyl ester, 24 mg (0.171 mmol) of 5-amino-1H-pyrazole-3-carboxylic acid methyl ester, 7 mg (20 mol %) of p-toluenesulfonic acid monohydrate (PTSA), and 3 mL of chlorobenzene was heated at 120° C. overnight. The reaction mixture was then concentrated to a residue which was purified via reverse-phase chromatography (Gilson) to afford (after lyophilization) desired 5-(4-benzyloxy-phenyl)-6-(2-cyclohexyl-ethyl)-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid methyl ester as a solid as indicated by LC-MS—calcd for C29H31N3O4 [M++H]+: 486.23, found: 486.2. This material was then converted to 5-(4-benzyloxy-phenyl)-6-(2-cyclohexyl-ethyl)-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid (559) via the well known LiOH saponification protocol (10% yield over 2 steps); LC-MS—calcd for C28H29N3O4 [M++H]+: 472.22, found: 472.2.

Provenance & Evidence