Hydrochloric Acid → 8-Indan-5-yl-2-methylsulfanyl-5-oxo-5,6,7,8-tetrahydro-pyrido[2,3-d]pyrimidine-6-carboxylic acid ethyl ester

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Reaction Conditions

Reaction Steps

To sodium (25 wt % dispersion in paraffin wax, 1.6 g, 16.9 mmol) was added t-butanol (30 mL) under stirring and N2. After 10 minutes, a solution of 4-[(2-ethoxycarbonyl-ethyl)-indan-5-yl-amino]-2-methylsulfanyl-pyrimidine-5-carboxylic acid ethyl ester (6.6 g, 15.4 mmol) in 40 mL of toluene was added to the sodium t-butoxide solution. The mixture was then heated at 90° C. for 30 minutes. The solution was cooled and poured into crushed ice. The solution was adjusted to pH 7 using HCl solution. The precipitates were extracted into EtOAc twice. The solvent was evaporated under vacuum and the product (bright yellow solid, 4 g, 62%) was recrystallized from isopropanol. 1H NMR (300 MHz, CDCl3) indicated that the presence of both enol and keto forms in a 4:1 ratio.

Provenance & Evidence