Hydrazine hydrate (1:1) → 3-Ethoxycarbonyl-5-(4-methyloxazol-5-yl)pyrazole

HRID 129840Notes

Reaction equation

HRID 129840 reaction equation
[CH2:1]([O:3][C:4](=[O:16])[C:5](=O)[CH2:6][C:7](=O)[C:8]1[O:12][CH:11]=[N:10][C:9]=1[CH3:13])[CH3:2].O.[NH2:18][NH2:19]>C(O)C>[CH2:1]([O:3][C:4]([C:5]1[CH:6]=[C:7]([C:8]2[O:12][CH:11]=[N:10][C:9]=2[CH3:13])[NH:19][N:18]=1)=[O:16])[CH3:2]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 510589382,4-Diketo4-(4-methyloxazol-5-yl)butyric acid ethyl ester

Product 1

HCID 1784687003-Ethoxycarbonyl-5-(4-methyloxazol-5-yl)pyrazoleYield 50.6%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2,4-diketo4-(4-methyloxazol-5-yl)butyric acid ethyl ester (8.50 g), hydrazine hydrate (1.88 g), and ethanol (100 ml) was refluxed for 3 hours and concentrated. The residue was chromatographed (silica gel, Hex/EtOAc 1/1) to yield 4.20 g of 3-ethoxycarbonyl-5-(4-methyloxazol-5-yl)pyrazole as tan solids, mp 131°-133° C. (methanol/isopropyl ether). NMR: 1.42 (t, 3H), 2.48 (s, 3H), 4.44 (q, 2H), 7.05 (s, 1H, 4-pyrazolyl H), 7.85 (s, 1H, 2-oxazolyl H).

Workup

  1. temperaturewas refluxed for 3 hours
  2. concentrationconcentrated
  3. customThe residue was chromatographed (silica gel, Hex/EtOAc 1/1)

Sources & evidence

ORD record
ord-ad0e54897cc94638951ecb4b8cd012ad
Source dataset
uspto-grants-1995_11
Patent number
US05470862

Reaction notes

Loading…