ChemicalBook CAS DataBase List 2,4,7-Trichloropyrido[2,3-d]pyrimidine

2,4,7-Trichloropyrido[2,3-d]pyrimidine synthesis

5synthesis methods

Product Name:2,4,7-Trichloropyrido[2,3-d]pyrimidine
CAS Number:938443-20-0
Molecular formula:C7H2Cl3N3
Molecular Weight:234.47

7-Chloropyrido[2,3-d]pyrimidine-2,4-diol

938443-19-7
63 suppliers
inquiry

938443-20-0
110 suppliers
$57.00/100mg

Yield: 48%

Reaction Conditions:

Stage #1:7-chloropyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione with N-ethyl-N,N-diisopropylamine in toluene at 70; for 0.5 h;
Stage #2: with trichlorophosphate in toluene at 20 - 100; for 2.5 h;

Steps:

d
d) 2,4, 7-Trichloro-pyrido[2,3-d]pyrimidine (Inter.5); To a stirred 0.5 M suspension of the dione (Inter. 4)(1 equiv.) in anhydrous toluene under an inert atmosphere was slowly added diisopropylethylamine (3 equiv.). The reaction mixture was then heated to 70⁰C for 30 minutes and then cooled to room temperature prior to the addition of POCl₃ (3 equivalents). The reaction was then heated to 100°C for 2.5 hours before being cooled and concentrated in vacuo to give a crude slurry which was then suspended in EtOAc and filtered through a thin pad of Celite. The filtrate was concentrated in vacuo to give a brown, oil which was dissolved in CH₂Cl₂ and stirred over silica gel for 30 minutes. After this time the silica was removed by filtration, the filtrate concentrated and the crude residue purified by flash chromatography (SiO₂) to give the title compound in analytically pure form (48% yield, 96% purity), m/z (LC-MS, ESP): 234 [M+H]⁺ R/T = 4.21 mins

References:

Location in patent:Page/Page column 57; 59