Pyridine → 4-Amino-6-(2-ethylbutyramido)quinazoline

To a mixture of 4,6-diaminoquinazoline hydrochloride (1.97 g), tripropylamine (2.60 g) and dry pyridine (20 ml) in an ice-bath was added dropwise during 10 minutes 2-ethylbutyryl chloride (1.75 g). The mixture was stirred for 3 hours at the same temperature. Crushed ice was added to the reaction mixture. The mixture was stirred for 5 minutes and concentrated under reduced pressure. After the addition of water (50 ml), sodium hydrogen carbonate (3.36 g) was added in small portions to the residue to give precipitates which were separated by filtration, washed with water and dried. The crude crystals were dissolved in a mixture of chloroform and methanol under heating. After insoluble materials were removed by filtration, the filtrate was concentrated under reduced pressure to give a residue, which was suspended in ethyl acetate. After stirring under heating, the suspension was filtered to give crystalline 4-amino-6-(2-ethylbutyramido)quinazoline (1.20 g).

1. additionCrushed ice was added to the reaction mixture
2. stirringThe mixture was stirred for 5 minutes
3. concentrationconcentrated under reduced pressure
4. additionAfter the addition of water (50 ml), sodium hydrogen carbonate (3.36 g)
5. additionwas added in small portions to the residue
6. customto give
7. customprecipitates which
8. customwere separated by filtration
9. washwashed with water
10. customdried
11. dissolutionThe crude crystals were dissolved in a mixture of chloroform and methanol
12. temperatureunder heating
13. customAfter insoluble materials were removed by filtration
14. concentrationthe filtrate was concentrated under reduced pressure
15. customto give a residue, which
16. stirringAfter stirring
17. temperatureunder heating
18. filtrationthe suspension was filtered

ORD record

ord-ae43a9f70ec44aebbc425fc972d2f400

Source dataset

uspto-grants-1983_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04377580