Urea → 5,6-Dihydrobenzo[h]quinazolin-2-ol

HRID 470321Notes

Reaction equation

HRID 470321 reaction equation
[CH2:1]1[CH2:11][C:9](=O)[C:8]2[C:3](=[CH:4][CH:5]=[CH:6][CH:7]=2)[CH2:2]1.[NH2:12][C:13]([NH2:15])=[O:14].[CH2:16](OC(OCC)OCC)C>CO.CS(O)(=O)=O>[N:12]1[C:9]2[C:8]3[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=3[CH2:2][CH2:1][C:11]=2[CH:16]=[N:15][C:13]=1[OH:14]

Participants

6

Reactant 3

HCID 1176UreaHCID 107241-TetraloneHCID 31214Ethyl orthoformate

Product 1

HCID 1785175485,6-Dihydrobenzo[h]quinazolin-2-olYield 35.6%

Reagents, catalysts & solvents 2

HCID 6395Methanesulfonic AcidCatalystHCID 887MethanolSolvent

Procedure

A mixture of alpha-tetralone (60 g, 0.41 M), urea (27 g, 0.45 M), triethylorthoformate (68 ml, 0.41 M), in methanol (80 ml) to which was then added methanesulfonic acid (100 drops) was heated at 100° C. for 30 min. then at 130° C. for 1 hr while allowing some solvent to distill off. The resulting thick suspension was cooled slurried with acetone (100 ml) and the solids isolated via filtration washing with acetone (2×80 ml). The solid was dried under reduced pressure overnight to afford 1 as a yellow solid (42.1 g as a 1:1 urea complex, 35.6% yield).

Workup

  1. distillationsome solvent to distill off
  2. temperatureThe resulting thick suspension was cooled
  3. customthe solids isolated via filtration
  4. washwashing with acetone (2×80 ml)
  5. customThe solid was dried under reduced pressure overnight

Sources & evidence

ORD record
ord-549785c9520740de951f837f2526e93c
Source dataset
uspto-grants-2014_01
Patent number
US08629147B2

Reaction notes

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