Diketene → N-(2-carbethoxycyclopentyl)-acetylacetamide
Reaction equation
[CH2:1]=[C:2]1[O:6][C:4](=[O:5])[CH2:3]1.[NH2:7][CH:8]1[CH2:12][CH2:11][CH2:10][CH:9]1[C:13]([O:15][CH2:16][CH3:17])=[O:14]>C1C=CC=CC=1>[C:13]([CH:9]1[CH2:10][CH2:11][CH2:12][CH:8]1[NH:7][C:4](=[O:5])[CH2:3][C:2](=[O:6])[CH3:1])([O:15][CH2:16][CH3:17])=[O:14]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 20 °C
Procedure
4.8 g of diketene were added to a mixture of 9 g of 1-amino-2-carbethoxy-cyclopentane and 90 ml of benzene and after stirring for 72 hours at 20° C., the mixture was evaporated to dryness under reduced pressure. The residue was chromatographed over silica gel and was eluted with an 8-2 methylene chloride-acetone mixture to obtain 7.7 g of N-(2-carbethoxycyclopentyl)-acetylacetamide with a refractive index of ND22 =1.487. 6.3 g of the latter product and 0.25 g of p-toluene sulfonic acid were added to a mixture of 4.2 g of methyl orthoformate and 60 ml of methanol and after stirring the mixture at 20° C. for 16 hours, the mixture was evaporated to dryness under reduced pressure. The residue was added to toluene and 0.5 ml of quinoline and the mixture was heated at 145° C. for 1 hour while distilling a toluene-methanol azeotrope. The mixture was evaporated to dryness under reduced pressure and the residue was chromatographed over silica gel. Elution with a 9-1 methylene chloride-acetone mixture gave 1.8 g of N-(2'-carbethoxycyclopentyl)-3-methoxy-crotonamide melting at 74° C. The RMN spectra showed it to be the E isomer.
Workup
- customthe mixture was evaporated to dryness under reduced pressure
- customThe residue was chromatographed over silica gel
- washwas eluted with an 8-2 methylene chloride-acetone mixture
Sources & evidence
- ORD record
- ord-7334f064af04473db1382b5771f01fa8
- Source dataset
- uspto-grants-1979_10
- Patent number
- US04170465
Reaction notes
Loading…