Hydrochloric Acid → 2-Amino-5,6,7,8-tetrahydroquinazolin-6-one

HRID 34657

Reaction equation

HRID 34657 reaction equation
[CH3:1][N:2]([CH:4]([N:8](C)C)[N:5](C)[CH3:6])C.C1(=O)[CH2:16][CH2:15][C:14](=[O:17])[CH2:13][CH2:12]1.C(=O)(O)O.NC(N)=N.Cl>C1(C)C=CC=CC=1.CO>[O:17]=[C:14]1[CH2:15][CH2:16][C:6]2[N:5]=[C:4]([NH2:8])[N:2]=[CH:1][C:12]=2[CH2:13]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 125111,4-CyclohexanedioneHCID 79831N,N,N',N',N'',N''-HexamethylmethanetriamineHCID 286947Carbonic acid-guanidine (1:1)

Product 1

HCID 212982302-Amino-5,6,7,8-tetrahydroquinazolin-6-one

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 1140TolueneSolvent2×

Procedure

A solution of tris(dimethylamino)methane, 25.0 g (172 mmol), in 100 ml toluene is added dropwise, under nitrogen, to a solution of the monoethylene ketal of 1,4-cyclohexanedione, 25.0 g (160 mmol), in 300 ml of toluene. The resulting solution is evaporated in-vacuo and the residue is dissolved in 600 ml of methanol along with 38.72 g (320 mmol) of guanidine carbonate. The pH of the solution is adjusted to 9 with 15% hydrochloric acid and the mixture is refluxed for 16 hours. The solvent is evaporated and the yellow residue is washed with cold water and recrystallized from absolute ethanol to yield 11.0 g of 5,6,7,8-tetrahydro-6-ketoquinazolin-2-amine, ethylene ketal as yellow prisms; mp 214°-217° C.

Workup

  1. customThe resulting solution is evaporated in-vacuo
  2. temperaturethe mixture is refluxed for 16 hours
  3. customThe solvent is evaporated
  4. washthe yellow residue is washed with cold water
  5. customrecrystallized from absolute ethanol

Sources & evidence

ORD record
ord-999f0d60f88a46828744633fb78cedb5
Source dataset
uspto-grants-1988_08
Patent number
US04762843

Linked notes

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