反应详情

温度

100 °C

3.26 G. of the crude sodium salt of hydroxymethylene-cyanacetaldehyde diethylacetal are dissolved in 20 ml. of water with stirring. 4.51 G. of p-n-propylbenzamidine hydrochloride are added and the resulting solution, which reacts alkaline, is adjusted to pH 4-5 with 1 ml. of 3-N hydrochloric acid. After stirring for 5 minutes, the mixture is concentrated to dryness at 50° C. in vacuo and the residue is left to stand at room temperature with 50 ml. of acetic anhydride for 16 hours. Then, the mixture is heated to 100° C. for 1 hour, evaporated in vacuo and the residue (brown oil, partly crystalline) is taken up in methylene chloride and chromatographed on silica gel. Elution with methylene chloride and methylene chloride/2% acetone yields 5-cyano-2-(4-n-propylphenyl)-pyrimidine, which is recrystallized from acetone/hexane to a constant melting point and then sublimed in a high vacuum at 120° C, whereby there are obtained colorless crystals of said pyrimidine having a melting point of 125.9°-126.0° C, which on cooling are liquid crystalline (monotropic) at 106.4° C.

1. customthe resulting solution, which reacts alkaline
2. concentrationthe mixture is concentrated to dryness at 50° C. in vacuo
3. waitthe residue is left
4. customto stand at room temperature with 50 ml
5. waitof acetic anhydride for 16 hours
6. customevaporated in vacuo
7. customchromatographed on silica gel
8. washElution with methylene chloride and methylene chloride/2% acetone