Guanidine Hydrochloride → Sodium ethoxide

HRID 1654342Notes

Reaction equation

HRID 1654342 reaction equation
[Na].Cl.[NH2:3][C:4]([NH2:6])=[NH:5].[Br:7][C:8]1[CH:17]=[C:16]2[C:11]([CH2:12][CH2:13][C:14](O)=[C:15]2[C:18]([O:20]CC)=[O:19])=[CH:10][CH:9]=1.[OH-].[Na+:25]>C(O)C>[O-:19][CH2:18][CH3:15].[Na+:25].[NH2:5][C:4]1[NH:6][C:18](=[O:20])[C:15]2[C:16]3[CH:17]=[C:8]([Br:7])[CH:9]=[CH:10][C:11]=3[CH2:12][CH2:13][C:14]=2[N:3]=1

Participants

7

Reactant 4

HCID 5742Guanidine HydrochlorideHCID 14798Sodium HydroxideHCID 5360545SodiumHCID 54708332HCID 54708332, compound

Product 2

HCID 2723922Sodium ethoxideHCID 1358381793-Amino-9-bromo-5,6-dihydrobenzo[f]quinazolin-1(4H)-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A solution of sodium ethoxide was prepared by adding freshly cut sodium (2.72 g, 118 mmoles) to absolute ethanol (350 ml). Guanidine hydrochloride (11.3 g, 118 mmoles) was added and the mixture was stirred and heated to reflux under a nitrogen atmosphere. A solution of ethyl 7-bromo-3,4-dihydro-2-hydroxy-1-naphthoate (11.72 g, 39.4 mmoles) in absolute ethanol (75 ml) was added dropwise over 2.5 hours. Refluxing was continued for an additional 21.5 hours, after which time the mixture was cooled to room temperature and filtered. Ethanol was evaporated under reduced pressure to give a yellow-colored foam which was dissolved in 0.1N NaOH (100 ml). The basic solution was extracted with ether and neutralized with acetic acid: water (1:9) to cause precipitation of the product. The precipitate was collected, washed with water and ether, and dried to give 3-amino-9-bromo-5,6-dihydrobenzo[f]quinazolin-1(2H)-one as an off-white powdery solid. (6.45 g, 53%) 1H NMR (DMSO-d6 , 80 MHz) δ: 2.45-2.90(m, 4H, CH2CH2); 6.80(br s, 2H, NH2); 7.03-7.29(m, 2H, ArH); 8.60-8.75(m, 1H, Ar); 11.0(br s, 1H, NH). Anal. Calculated for C12H10BrN3O.H2O C, 46.47; H, 3.90; Br, 25.76; N, 13.55. Found: C, 46.58; H, 3.85; N, 13.60; Br, 25.87.

Workup

  1. temperatureheated
  2. temperatureto reflux under a nitrogen atmosphere
  3. temperatureRefluxing
  4. filtrationfiltered
  5. customEthanol was evaporated under reduced pressure
  6. customto give a yellow-colored foam which
  7. extractionThe basic solution was extracted with ether and neutralized with acetic acid: water (1:9)
  8. customprecipitation of the product
  9. customThe precipitate was collected
  10. washwashed with water and ether
  11. customdried

Sources & evidence

ORD record
ord-50fa5e8e9a9a455b871561b74eb6d12d
Source dataset
uspto-grants-1995_04
Patent number
US05405851

Reaction notes

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