2H-Pyrrol-2-one → HCID 67783663, compound

HRID 1742927Notes

Reaction equation

HRID 1742927 reaction equation
[N:1]1[C:2](=[O:6])[CH:3]=[CH:4][CH:5]=1.[C:7]([O:10][C:11](=[O:13])[CH3:12])(=[O:9])[CH3:8].N1C=CC=CC=1.CS(C)=O.[Cl-].[Na+].O>[Ag]=O.CO.[Pd]>[C:7]([OH:10])(=[O:9])[CH3:8].[C:2]([N:1]1[CH:5]=[CH:4][CH2:12][C:11]1=[O:13])(=[O:6])[CH3:3]

Participants

6

Reactant 3

HCID 142467952H-Pyrrol-2-oneHCID 22348678Acetic anhydride pyridineHCID 86608888HCID 86608888, compound

Product 1

HCID 67783663HCID 67783663, compound

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 86748092HCID 86748092, compoundCatalyst

Procedure

A pyrrolone to act as a dienophile for cycloaddition to the triene 15 is prepared as follows. Methyl L-3-amino-(substituted phenyl)butyrate 16 is prepared from the appropriately substituted N-carbobenzoxy-L-alanine by Arndt-Eistert homologation, via the silver oxide-methanol rearrangement of the diazo ketone, followed by 10% Pd/C hydrogenolysis. The amino ester 16 is converted into the hydroxypyrrolone ester 17 by the method of Southwick, P. L., and R. T. Crouch, J. Am. Chem. Soc. 75:3413 (1953). The hydroxypyrrolone ester 17 is then treated with acetic anhydride-pyridine, with 4-N,N-dimethylaminopyridine as catalyst, for thirty minutes at room temperature, followed by hydrolysis-decarboxylation, using dimethyl sulfoxide-sodium chloride-water (50:28: 1), at 135°-140° C. for 1.5 hours in a nitrogen atmosphere. The liberated hydroxyl is then reacetylated, and the N-acetyl pyrrolone acetate 18 is isolated by chromatography on silica, using 4:1 hexane-ethyl acetate followed by 3:2 chloroform-ethyl acetate. ##STR6##

Workup

  1. customis prepared
  2. customfollowed by hydrolysis-decarboxylation

Sources & evidence

ORD record
ord-814b35afe67542f5a7cdc402ed307054
Source dataset
uspto-grants-1994_08
Patent number
US05342926

Reaction notes

Loading…