Hydrochloric Acid → (R)-tert-Butyl 1-(3-benzyl-7-chloro-4-oxo-3,4-dihydroquinazolin-2-yl)-2-methylpropylcarbamate

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Reaction Steps

A dry 3-necked, round bottomed flask, equipped with a magnetic stirrer, nitrogen inlet, heating mantle and a water condenser, is charged with 60 mL of 1,4-dioxane/ethylene glycol (2:1), 4.60 g (10 mmol) of (R)-{1-[(2-benzylcarbamoyl-5-chloro-phenylimino)-methyl]-2-methyl-propyl}-carbamic acid tert-butyl ester (a compound of Formula 106, obtained as described in Example 5.3), and 0.46 g (11 mmol) of lithium hydroxide monohydrate. The mixture is heated to reflux and the reaction is monitored by TLC (hexanes/ethyl acetate 7:3). After 4 h of refluxing the reaction appears to be complete. The mixture is allowed to cool to room temperature and is slowly acidified to pH=5 by adding 1N hydrochloric acid. The mixture is stirred for 1 h and the white suspension is separated by filtration and dried in high vacuum to afford the title compound of Formula 107, (R)-[1-(3-benzyl-7-chloro-4-oxo-3,4-dihydro-quinazolin-2-yl)-2-methylpropyl]-carbamic acid tert-butyl ester.

Provenance & Evidence