Hydrogen Peroxide → 4,4-Diethyl-4,5-dihydro-3H-pyrazole

2,2-Diethyl-propane-1,3-diamine (5.0 g) was taken up in a mixture of H2O (40 mL) and MeOH (10 mL), and cooled in an ice bath. Simultaneously, H2O2 (24.2 mL of a 30% solution, 6 equiv.) and NaClO (54.9 mL of a 10% solution, 2.4 equiv.) were added dropwise, the ice bath was removed, and the mixture was stirred for 2 h. at room temperature. Extraction with DCM, drying over Na2SO4 and evaporation under reduced pressure yielded 3.51 g of a clear, yellow liquid containing 77% of the anticipated product and 23% of the diamine starting material. This material was used in subsequent steps without further purification. 1H NMR (400 MHz, CDCl3) δ 0.78 (t, J=7.5 Hz, 6H), 1.36 (q, J=7.5 Hz, 4H), 4.14 (s, 4H).

1. temperaturecooled in an ice bath
2. customthe ice bath was removed
3. extractionExtraction with DCM
4. dry with materialdrying over Na2SO4 and evaporation under reduced pressure
5. customyielded 3.51 g of a clear, yellow liquid

ORD record

ord-a9d77dddad274685bd831afc3efc3579

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08722887B2