Triphenylphosphine → 6-Methoxy-7-(3-methylsulphonylpropoxy)-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-4-one

Beteiligte Stoffe

Reaktionsschritte

Triphenylphosphine (8.9 g, 35.2 mmol) was added to a suspension of 7-hydroxy-6-methoxy-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-4-one (6 g, 19.6 mmol), (prepared as described for the starting material in Example 12), in methylene chloride (150 ml). This was followed by the addition of 3-(methylsulphonyl)-1-propanol (3.5 g, 25.4 mmol) and diethyl azodicarboxylate (5.55 ml, 35.2 mmol) in portions. The reaction was complete once the reaction became homogeneous. Silica was added and the volatiles were removed by evaporation. The free flowing powder was placed on the top of a flash chromatography column pre-equilibrated with ethyl acetate (100%). Elution was done using ethyl acetate (100%) followed by methylene chloride/ethyl acetate/methanol (60/35/5). The volatiles were removed by evaporation to give 6-methoxy-7-(3-methylsulphonylpropoxy)-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-4-one (7.58 g, 91%) as a white solid.

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