Water → 6-Acetoxy-7-methoxy-3H-quinazolin-4-one

HRID 2233248Notes

Reaction equation

CO[C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[N:9]=[CH:8][NH:7][C:6]2=[O:15].N[C@H:17](C(O)=O)[CH2:18]CSC.[OH2:25].[OH-:26].[Na+]>CS(O)(=O)=O>[C:17]([O:26][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[N:9]=[CH:8][NH:7][C:6]2=[O:15])(=[O:25])[CH3:18]

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of 6,7-dimethoxy-3,4-dihydro-quinazolin-4-one (20.0 g, 97 mmol) and racemic methionine (21.7 g, 146 mmol) in methanesulphonic acid (150 ml) were heated at 100° C. for 5.5 hours and then allowed to cool to ambient temperature over 18 hours. The reaction was poured into cold water (750 ml), the pH of the aqueous solution was adjusted to pH 6 (by addition of 2.0N aqueous sodium hydroxide solution) and the solid which formed was collected by suction filtration. The solid was dried in vacuo and then dissolved in a mixture of pyridine (20 ml) and acetic anhydride (150 ml). The solution was heated at 100° C. for 1 hour, cooled and poured into cold water (1050 ml). Collection of the resultant solid by suction filtration, followed by drying in vacuo, yielded 6-acetoxy-7-methoxy-3,4-dihydro-quinazolin-4-one (13.9 g, 57% yield) as a pale-brown solid:

Workup

temperatureto cool to ambient temperature over 18 hours
customthe solid which formed
filtrationwas collected by suction filtration
customThe solid was dried in vacuo
dissolutiondissolved in a mixture of pyridine (20 ml) and acetic anhydride (150 ml)
temperatureThe solution was heated at 100° C. for 1 hour
temperaturecooled
additionpoured into cold water (1050 ml)
customCollection of the resultant solid
filtrationby suction filtration
customby drying in vacuo

Sources & evidence

ORD record: ord-9791106af10f4b56b011c4c30a5d1afa
Source dataset: uspto-grants-2010_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07709479B1

Reaction notes

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