Urea → 6-Amino-3-methyl-1-phenylpyrimidine-2,4(1H,3H)-dione

HRID 2258470Notes

Reaction equation

[CH3:1][NH:2]C(NC1C=CC=CC=1)=O.[C:12]1([N:18]=[C:19]=[O:20])[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.CN.NC(N)=O.[C:27]([CH2:29][C:30]([OH:32])=O)#[N:28]>C(OC(=O)C)(=O)C>[NH2:28][C:27]1[N:18]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[C:19](=[O:20])[N:2]([CH3:1])[C:30](=[O:32])[CH:29]=1

Participants

Conditions

Temperature: 80 °C

Procedure

N-Methyl-N'-phenylurea was preliminarily prepared from phenyl isocyanate and methylamine by the procedure described in Step 1. Using the urea compound as the starting material, uracil ring was formed by the procedure described in Step 2. N-Methyl-N'-phenylurea (30 g, 0.2M) and cyanoacetic acid (18.8 g, 0.22M) were dissolved in 400 ml of a solvent, acetic anhydride, and heated at 80° C. for 2 hours. The solvent acetic anhydride was distilled off under reduced pressure and 200 ml of water was added to the residue, followed by cooling with ice. A 2N aqueous solution of NaOH (220 ml) was then added and the mixture was stirred for 2 hours. A precipitated solid product was obtained by filtration. The solid product was washed successively with water and methanol and dried to yield 6-amino-3-methyl-1-phenyluracil (yield: 33 g, or 76% based on N-methyl-N'-phenylurea).

Workup

customuracil ring was formed by the procedure
distillationThe solvent acetic anhydride was distilled off under reduced pressure and 200 ml of water
additionwas added to the residue
temperatureby cooling with ice
additionA 2N aqueous solution of NaOH (220 ml) was then added
customA precipitated solid product was obtained by filtration
washThe solid product was washed successively with water and methanol
customdried

Sources & evidence

ORD record: ord-de9355c32b414574a9f886dc2aeda53c
Source dataset: uspto-grants-1997_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05661153

Reaction notes

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