Dicyclohexylcarbodiimide → t-Butyl 3-Ethyl-7beta-phenylthioacetamidoceph-3-em-4-carboxylate

HRID 1282994Notes

Reaction equation

HRID 1282994 reaction equation
C1(N=C=NC2CCCCC2)CCCCC1.[NH2:16][C@@H:17]1[C:33](=[O:34])[N:19]2[C:20]([C:26]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])=[O:27])=[C:21]([CH2:24][CH3:25])[CH2:22][S:23][C@H:18]12.[C:35]1([CH2:41][C:42](O)=[S:43])[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1.N=C=N>C(Cl)Cl>[CH2:24]([C:21]1[CH2:22][S:23][C@@H:18]2[C@H:17]([NH:16][C:42](=[S:43])[CH2:41][C:35]3[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=3)[C:33](=[O:34])[N:19]2[C:20]=1[C:26]([O:28][C:29]([CH3:30])([CH3:32])[CH3:31])=[O:27])[CH3:25]

Participants

6

Reactant 4

HCID 10868DicyclohexylcarbodiimideHCID 160435CarbodiimideHCID 131710422t-Butyl 7beta-amino-3-ethylceph-3-em-4-carboxylateHCID 178526157HCID 178526157, compound

Product 1

HCID 131710421t-Butyl 3-Ethyl-7beta-phenylthioacetamidoceph-3-em-4-carboxylate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

A solution of N,N'-dicyclohexylcarbodiimide (620 mg, 3 mmole) in dry methylene chloride (15 ml.) was added to a stirred solution of t-butyl 7β-amino-3-ethylceph-3-em-4-carboxylate (853 mg. 3 mmole) in dry methylene chloride (10 ml.). A solution of phenylthioacetic acid (505 mg. 3 mmole) in dry methylene chloride (10 ml.) was added over 5 minutes to the mixture which was stirred at ca. 20° for 2 hours. A further portion of carbodiimide (124 mg., 0.6 mmole) was added, and the mixture was stirred for a further 30 minutes and filtered from precipitated N,N'-dicyclohexylurea. The filtrate was washed successively with 3% aqueous sodium hydrogen carbonate solution (50 ml.), water (50 ml.), 2N-hydrochloric acid (25 ml.) and water (25 ml.), dried (MgSO4) and evaporated to a yellow oil which was dissolved in ethyl acetate (8 ml.). The solution was cooled, the precipitated dicyclohexylurea was removed by filtration, and the filtrate was evaporated to give the title ester as a pale yellow foam (1.45 g.), [α]D23 + 67° (c 1.05; CHCl3), λmax. (EtOH) 250.5 nm (E1 cm.1% 256), contaminated with ca. 15% by weight of N,N'-dicyclohexylurea and/or the corresponding N-acylurea. The infra red (CHBr3) and p.m.r. (CDCl3) spectra of the product were in accord with the assigned structure.

Workup

  1. stirringthe mixture was stirred for a further 30 minutes
  2. filtrationfiltered
  3. customfrom precipitated N,N'-dicyclohexylurea
  4. washThe filtrate was washed successively with 3% aqueous sodium hydrogen carbonate solution (50 ml.), water (50 ml.), 2N-hydrochloric acid (25 ml.) and water (25 ml.)
  5. dry with materialdried (MgSO4)
  6. customevaporated to a yellow oil which
  7. dissolutionwas dissolved in ethyl acetate (8 ml.)
  8. temperatureThe solution was cooled
  9. customthe precipitated dicyclohexylurea was removed by filtration
  10. customthe filtrate was evaporated

Sources & evidence

ORD record
ord-743b2aa94fa24fbc9837b0cc3015af5a
Source dataset
uspto-grants-1976_08
Patent number
US03974152

Reaction notes

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