Hydroxyamine hydrochloride → Ethyl 5-(2,4-bis(benzyloxy)-5-chlorophenyl)isoxazole-3-carboxylate

HRID 1891138Notes

Reaction equation

HRID 1891138 reaction equation
Cl.[NH2:2]O.[CH2:4]([O:6][C:7](=[O:36])[C:8](O)=[CH:9][C:10]([C:12]1[CH:17]=[C:16]([Cl:18])[C:15]([O:19][CH2:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)=[CH:14][C:13]=1[O:27][CH2:28][C:29]1[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=1)=[O:11])[CH3:5]>C(O)C>[CH2:4]([O:6][C:7]([C:8]1[CH:9]=[C:10]([C:12]2[CH:17]=[C:16]([Cl:18])[C:15]([O:19][CH2:20][C:21]3[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=3)=[CH:14][C:13]=2[O:27][CH2:28][C:29]2[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=2)[O:11][N:2]=1)=[O:36])[CH3:5]

Participants

4

Reactant 2

HCID 443297Hydroxyamine hydrochlorideHCID 178473089HCID 178473089, compound

Product 1

HCID 24774040Ethyl 5-(2,4-bis(benzyloxy)-5-chlorophenyl)isoxazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Hydroxylamine hydrochloride (0.89 g; 12.8 mmol) was added to a suspension of 4-(2,4-bis-benzyloxy-5-chlorophenyl)-2-hydroxy-4-oxo-but-2-enoic acid ethyl ester (5.00 g; 10.7 mmol) in absolute ethanol (100 ml). The reaction mixture was heated at reflux for four hours then allowed to cool to ambient temperature (during this time the mixture remains heterogeneous but becomes lighter yellow in colour). The mixture was filtered and the filtered solid was washed with water (2×20 ml), ethanol (2×20 ml) and dried in vacuo at 45° C. This affords 5-(2,4-bis-benzyloxy-5-chlorophenyl)-isoxazole-3-carboxylic acid ethyl ester as a fluffy yellow solid, 4.49 g (91%) LCMS: [M+H]+ 466, 464 (37Cl; 35Cl)). 1H NMR (400 MHz, CDCl3) δ 1.42 (t, 3H), 4.42 (q, 2H), 5.13 (s, 2H), 5.14 (s, 2H), 6.62 (s, 1H), 7.01 (s, 1H), 7.35-7.43 (m, 10H), 8.00 (s, 1H).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for four hours
  3. filtrationThe mixture was filtered
  4. washthe filtered solid was washed with water (2×20 ml), ethanol (2×20 ml)
  5. customdried in vacuo at 45° C

Sources & evidence

ORD record
ord-3b66c7fa5df849549ba4cc4773f3beb0
Source dataset
uspto-grants-2013_08
Patent number
US08507480B2

Reaction notes

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