Water → 2,5-Diamino-4,6-dichloropyrimidine

A mixture of 2-amino-4,6-dichloro-5-[(dimethylamino)methylene]amino}pyrimidine (Example 2, 500 mg, 2.14 mmol), pH 3.2 aqueous potassium phosphate buffer (1.5 M, 6 mL, prepared as described in Example 3), water (1 mL), and ethanol (5 mL) was refluxed gently for 28 hours. During the reflux period, pH was maintained at ca. 3 by addition of 85% phosphoric acid. Volatiles were evaporated in vacuo and the residual solids partitioned between water (30 mL, adjusted to ph 8 with dilute ammonium hydroxide) and chloroform (75 mL). The chloroform layer was dried (sodium sulfate) and the chloroform evaporated to leave off-white solid (0.30 g). Crystallization of this solid from ethanol:water/4:1 gave the title compound (IV) as light pink needles (332 mg, 61%); darkens and shrinks to black solid above 185° C., does not become fluid below 300° C.; 1H-NMR (DMSO-d6) and mass spectra identical to those described in Example 4.

1. temperaturewas refluxed gently for 28 hours
2. customVolatiles were evaporated in vacuo
3. customthe residual solids partitioned between water (30 mL, adjusted to ph 8 with dilute ammonium hydroxide) and chloroform (75 mL)
4. dry with materialThe chloroform layer was dried (sodium sulfate)
5. customthe chloroform evaporated

ORD record

ord-ed48cc320a154cacbb03ea3a567ee6df

Source dataset

uspto-grants-1999_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05917041