Phosphoric Acid → N-(2-Amino-4,6-dichloropyrimidin-5-yl)formamide

HRID 1417003Notes

Reaction equation

[NH2:1][C:2]1[N:7]=[C:6]([Cl:8])[C:5]([N:9]=[CH:10]N(C)C)=[C:4]([Cl:14])[N:3]=1.P([O-])([O-])([O-])=[O:16].[K+].[K+].[K+].OP([O-])(O)=O.[K+].P(=O)(O)(O)O>P(=O)(O)(O)O.CO.C(Cl)(Cl)Cl>[NH2:1][C:2]1[N:7]=[C:6]([Cl:8])[C:5]([NH:9][CH:10]=[O:16])=[C:4]([Cl:14])[N:3]=1

Participants

Conditions

Temperature: 125 °C

Procedure

A slurry of 2-amino-4,6-dichloro-5-{[(dimethylamino)methylene]amino}pyrimidine (Example 2, 1.50 g, 6.41 mmol) and 1.5 M aqueous potassium phosphate buffer (35 mL, prepared by adjusting the pH of a 1.5 M solution of KH2PO4 to 3.2 by addition of 85% phosphoric acid) was gently refluxed (in an oil bath at 125° C.) After 4 hours of reflux, the pH of the mixture was adjusted from 4 to 3 by addition of 4 drops of 85% phosphoric acid. After a total of 6 hours of reflux, TLC (silica gel plated developed in 5% methanol-chloroform) showed that the starting material had been largely converted to a lower-Rf product. The solid was filtered and washed with water (5 mL), methanol (5 mL), and dried to give the title compound as a white solid (0.900 g, 68%), m.p.>250° C. dec.; mass spectrum (Cl/CH4): 209, 207 (M+1); 1H-NMR (DMSO-d6)δ: 9.81 and 9.46 (s and d, J=11 Hz, total 1, NH), 8.25 and 8.00 (s and d, J=11 Hz, total 1, CHO), 7.69 and 7.63 (both s, total 2, NH2).

Workup

temperatureof reflux
temperatureAfter a total of 6 hours of reflux
filtrationThe solid was filtered
washwashed with water (5 mL), methanol (5 mL)
customdried

Sources & evidence

ORD record: ord-98831cf3b1eb487b876162044c3df12b
Source dataset: uspto-grants-1999_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05917041

Reaction notes

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