Urea → Ethyl 4-hydroxy-3-methylbenzoate

HRID 654214

Reaction equation

N[C:2]1[CH:12]=[CH:11][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH:4][C:3]=1[CH3:13].[OH:14]S(O)(=O)=O.O.N([O-])=O.[Na+].NC(N)=O>O>[OH:14][C:2]1[CH:12]=[CH:11][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH:4][C:3]=1[CH3:13]

Participants

Conditions

Temperature: 5 °C

Procedure

Ethyl 4-amino-3-methylbenzoate (3.85 g; 21.5 mmol) was dissolved in hot, 35% H2SO4 /water and the mixture then cooled to below 5° C. An ice-cold solution of 1.91 g (22.5 mmol) of sodium nitrite in 20 ml of water was then slowly added to the mixture such that the temperature of the mixture never exceeded 5° C. The mixture was stirred at 5° C. for 10 minutes and then treated with 1 g of urea and stirred for a further 10 minutes. A solution of 50 g (207 mmol) of cupric nitrate trihydrate in 750 ml of water was added to the reaction mixture followed by 2.87 g of cuprous oxide. The mixture was stirred for a further 15 minutes and then extracted with 3×300 ml ether. The ether extracts were combined and then washed with water and saturated NaCl solution and then dried (MgSO4). The solution was filtered, the solvent removed in-vacuo and the residue purified by flash chromatography (silica; 13% ethyl acetate in hexanes to 20% ethyl acetate in hexanes) to give the title compound as a pale yellow solid.

Workup

temperaturethe mixture then cooled to below 5° C
stirringstirred for a further 10 minutes
stirringThe mixture was stirred for a further 15 minutes
extractionextracted with 3×300 ml ether
washwashed with water and saturated NaCl solution
dry with materialdried (MgSO4)
filtrationThe solution was filtered
customthe solvent removed in-vacuo
customthe residue purified by flash chromatography (silica; 13% ethyl acetate in hexanes to 20% ethyl acetate in hexanes)

Sources & evidence

ORD record: ord-7a86c16b111c4fefba2130ad23285b40
Source dataset: uspto-grants-1992_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05130335

Linked notes

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