Propargyl acetate → 2-[(Acetyloxy)methyl]pyrazolo[1,5-c]quinazolin-5(6H)-one

2.0 g of diazooxindole (0.013 mole) and 12.8 g (0.13 mole or 10 equivalents) of propargyl acetate are refluxed under argon for 4 hours. The reaction mixture is cooled, diluted with 200 ml of ether, stirred for 30 minutes and filtered. The light tan product is washed with ether, dried in vacuo for 1 hour at room temperature and treated with activated charcoal in a mixture of ethanol (200 ml) and ethyl acetate (100 ml). The reaction mixture is filtered through a Celite pad, concentrated to a volume ~100 ml, diluted with 100 ml ethyl acetate and concentrated to a volume of 50 ml. Another 100 ml of ethyl acetate is added, the resulting solution is concentrated to a volume of 50 ml and cooled to 0°-5°. The title compound is filtered off and dried.

1. temperatureThe reaction mixture is cooled
2. filtrationfiltered
3. washThe light tan product is washed with ether
4. customdried in vacuo for 1 hour at room temperature
5. additiontreated with activated charcoal in a mixture of ethanol (200 ml) and ethyl acetate (100 ml)
6. filtrationThe reaction mixture is filtered through a Celite pad
7. concentrationconcentrated to a volume ~100 ml
8. additiondiluted with 100 ml ethyl acetate
9. concentrationconcentrated to a volume of 50 ml
10. additionAnother 100 ml of ethyl acetate is added
11. concentrationthe resulting solution is concentrated to a volume of 50 ml
12. temperaturecooled to 0°-5°
13. filtrationThe title compound is filtered off
14. customdried

ORD record

ord-e850eb8410a04d6fa564ac03419cfbf0

Source dataset

uspto-grants-1978_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04076818