Hydrochloric Acid → (R)-[1-(7-chloro-4-oxo-3,4-dihydro-quinazolin-2-yl)-2-methylpropyl]-carbamic acid tert-butyl ester

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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 THF, 3.70 g (10 mmol) of (R)-{1-[(2-carbamoyl-5-chloro-phenylimino)-methyl]-2-methyl-propyl}-carbamic acid tert-butyl ester (the compound of Formula 201 prepared, e.g., as described in Example 6.1), and 0.46 g (11 mmol) of lithium hydroxide monohydrate. The mixture is heated to reflux and the reaction monitored by TLC (hexanes/ethyl acetate 7:3) by which, after 1 h of refluxing, the reaction is shown to be complete. The mixture is allowed to cool to room temperature and transferred to a round bottom 1-necked flask followed by dilution with 60 mL of water. The stirring mixture is then slowly acidified to pH=5 by adding 1N hydrochloric acid and the THF is removed by rotary evaporation. The white suspension is separated by filtration and dried in high vacuum to afford the title compound of Formula 202, (R)-[1-(7-chloro-4-oxo-3,4-dihydro-quinazolin-2-yl)-2-methylpropyl]-carbamic acid tert-butyl ester.

Provenance & Evidence