Sodium Bicarbonate → Cephalothin

HRID 1658030Notes

Reaction equation

HRID 1658030 reaction equation
[C:1]([O:4][CH2:5][C:6]1[CH2:7][S:8][C@@H:9]2[C@H:16]([NH:17][C:18](=[O:25])[CH2:19][C:20]3[S:21][CH:22]=[CH:23][CH:24]=3)[C:15](=[O:26])[N:10]2[C:11]=1[C:12]([O-:14])=[O:13])(=[O:3])[CH3:2].C(=O)(O)[O-].[Na+]>C1(OC)C=CC=CC=1>[C:1]([O:4][CH2:5][C:6]1[CH2:7][S:8][C@@H:9]2[C@H:16]([NH:17][C:18](=[O:25])[CH2:19][C:20]3[S:21][CH:22]=[CH:23][CH:24]=3)[C:15](=[O:26])[N:10]2[C:11]=1[C:12]([OH:14])=[O:13])(=[O:3])[CH3:2]

Participants

4

Reactant 2

HCID 516892Sodium BicarbonateHCID 7048634HCID 7048634, compound

Product 1

HCID 6024CephalothinYield 94.4%

Reagents, catalysts & solvents 1

HCID 7519AnisoleSolvent

Procedure

A suspension of p-methoxybenzyl dl-3-acetoxymethyl-7β-(2-thienylacetamido)-3-cephem-4-carboxylate (13.8 mg., 0.027 mMol) in anisole (70 μl.) is cooled in an ice-bath. Ice-cold trifluoroacetic acid (350 μl.) is added and the mixture is swirled to make it homogeneous. The resulting solution is kept at 0°C. for 5 minutes, then evaporated in vacuo at 0°C. to remove excess trifluoroacetic acid. The oily residue is allowed to warm to room temperature under vacuum, then diluted with anisole (0.5 ml.) and evaporated in vacuo at 35°C. The resulting semi-solid is taken up in water (5 ml.) containing sodium bicarbonate (23 mg., 0.27 mMol) and the solution is extracted with methylene chloride (3 × 2 ml.). The aqueous phase (pH 8.65) is acidified to pH 2.6 with 1 M pH 2 phosphate and is extracted with ethyl acetate (4 × 3 ml.). The combined extracts are dried over magnesium sulfate, filtered, and evaporated in vacuo to yield dl-3-acetoxymethyl-7β-(2-thienylacetamido)-3-cephem-4-carboxylic acid (10.1 mg.) as a white solid: ir (neat) 2.8-4.5, 5.60, 5.76, 5.91, 6.50, 7.23, 8.10 and 9.63μ; nmr (Me2CO-d6) τ 7.96 (s, 3, CH3CO), 6.58, 6.20 (dd, 2, J=19Hz, 2-CH2), 6.08 (s, 2, ArCH2), 5.20, 4.83 (dd, 2, J=13Hz, CH2OAc), 4.86 (d, 1, J=4.5Hz, H6), 4.13 (d of d, 1, J=4.5Hz and J-9Hz. H7), 2.85 (m, 3, ArH), and 1.96 (d, 1, J=9Hz, NH).

Workup

  1. temperatureis cooled in an ice-bath
  2. customevaporated in vacuo at 0°C.
  3. customto remove excess trifluoroacetic acid
  4. additiondiluted with anisole (0.5 ml.)
  5. customevaporated in vacuo at 35°C
  6. extractionthe solution is extracted with methylene chloride (3 × 2 ml.)
  7. extractionis extracted with ethyl acetate (4 × 3 ml.)
  8. dry with materialThe combined extracts are dried over magnesium sulfate
  9. filtrationfiltered
  10. customevaporated in vacuo

Sources & evidence

ORD record
ord-ee1ee324b4184bad8751bfdb58ed99fa
Source dataset
uspto-grants-1976_06
Patent number
US03962224

Reaction notes

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