Hydrochloric Acid → tert-Butyl 4-(((6-methoxy-4-oxo-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-7-yl)oxy)methyl)piperidine-1-carboxylate

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Reaction Steps

A suspension of 7-hydroxy-6-methoxy-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-4-one (6.12 g, 20 mmol) potassium carbonate (5.52 g, 40 mmol) in DMF (60 ml) was stirred at ambient temperature for 30 minutes. 4-(4-Methylphenylsulphonyloxymethyl)-1-tert-butyloxycarbonylpiperidine (8.86 g, 24 mmol), (prepared as described for the starting material in Example 10), was added and the mixture was stirred at 100° C. for 2 hours. After cooling, the mixture was poured onto water/ice (400 ml, 1/1) containing 2M hydrochloric acid (10 ml). The precipitate was collected by filtration, washed with water and dried under vacuum over phosphorus pentoxide. The solid was triturated in a mixture of ether/pentane (1/1), collected by filtration and dried to give 6-methoxy-3-((pivaloyloxy)methyl)-7-((1-tert-butyloxycarbonylpiperidin-4-yl)methoxy)-3,4-dihydroquinazolin-4-one (7.9 g, 78.5%).

Provenance & Evidence