Phosphorus oxychloride → 2-Amino-4-chloro-6-phenylpyrimidine

HRID 1355703Notes

Reaction equation

[NH2:1][C:2]1[NH:7][C:6](=O)[CH:5]=[C:4]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[N:3]=1.P(Cl)(Cl)([Cl:17])=O>[OH-].[NH4+]>[Cl:17][C:6]1[CH:5]=[C:4]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[N:3]=[C:2]([NH2:1])[N:7]=1

Participants

Conditions

Temperature: 70 °C

Procedure

A stirred suspension of 3.69 g (19.7 mmol) 2-amino-6-phenyl-3H-pyrimidin-4-one in 4.5 ml (49.2 mmol) phosphorus oxychloride was heated at reflux for 2 h. The reaction mixture was then cooled to about 70° C. and poured cautiously onto 20 ml rapidly stirred ice-water. The mixture was briefly warmed to room temperature and then was recooled to 0° C. 100 ml 25% ammonium hydroxide solution was added and the resulting crystals were collected by filtration and washed with ice-cold water and then with a little ether to afford 3.49 g (86%) 4-chloro-6-phenyl-pyrimidin-2-ylamine as a pale yellow crystalline solid. EI-MS m/e (%): 207 (M{37Cl}+, 35), 206 ([M{37Cl}—H]+, 30)., 205 (M{35Cl}+, 100), 204 ([M{35Cl}—H]+, 56), 170 ([M—Cl]+, 35), 128 (([M—C6H5]+, 85).

Workup

temperaturewas heated
temperatureat reflux for 2 h
temperatureThe mixture was briefly warmed to room temperature
customwas recooled to 0° C
filtrationthe resulting crystals were collected by filtration
washwashed with ice-cold water

Sources & evidence

ORD record: ord-af17b6ec6842426b937a4fbf93d6da39
Source dataset: uspto-grants-2003_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06586441B2

Reaction notes

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