1,4-Dioxane → (2R,3S,5R,6R) 2-(N-Acetyl)carbamoyloxymethyl-2-methyl-6-phenylacetamidopenam-3 carboxylic Acid p-Nitrobenzyl Ester

HRID 647075Notes

Reaction equation

HRID 647075 reaction equation
[N+:1]([C:4]1[CH:34]=[CH:33][C:7]([CH2:8][O:9][C:10]([C@@H:12]2[N:16]3[C:17](=[O:29])[C@@H:18]([NH:19][C:20](=[O:28])[CH2:21][C:22]4[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=4)[C@H:15]3[S@@:14](=O)[C:13]2([CH3:32])[CH3:31])=[O:11])=[CH:6][CH:5]=1)([O-:3])=[O:2].[C:35]([N:38]=[C:39]=[O:40])(=[O:37])[CH3:36].[O:41]1CCOCC1>>[N+:1]([C:4]1[CH:34]=[CH:33][C:7]([CH2:8][O:9][C:10]([C@@H:12]2[N:16]3[C:17](=[O:29])[C@@H:18]([NH:19][C:20](=[O:28])[CH2:21][C:22]4[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=4)[C@H:15]3[S:14][C@:13]2([CH2:32][O:40][C:39](=[O:41])[NH:38][C:35](=[O:37])[CH3:36])[CH3:31])=[O:11])=[CH:6][CH:5]=1)([O-:3])=[O:2]

Participants

4

Reactant 3

HCID 312751,4-DioxaneHCID 12300404Acetyl isocyanateHCID 15403223(1S,3S,5R,6R) 2,2-dimethyl-6-phenylacetamidopenam-3-carboxylic acid-1-oxide p-nitrobenzyl ester

Product 1

HCID 12817543(2R,3S,5R,6R) 2-(N-Acetyl)carbamoyloxymethyl-2-methyl-6-phenylacetamidopenam-3 carboxylic Acid p-Nitrobenzyl EsterYield 45%

Procedure

A solution of (1S,3S,5R,6R) 2,2-dimethyl-6-phenylacetamidopenam-3-carboxylic acid-1-oxide p-nitrobenzyl ester (4.85 g, 10.0 mmol) and acetyl isocyanate (2.3 ml, 30 mmol) in dioxane (50 ml) was refluxed under nitrogen for 7 hours. The light orange solution was concentrated in vacuo to a foam which was chromatographed on silica gel (500 g) with methylene chloride:acetone; 9:1, v:v. Two major bands were eluted; the first was the Δ3 3-methylcephem (28%, 1.29 g) and the second was the title compound obtained in 45% yield (2.56 g) as an off-white foam: mp 83°-85°; nmr 100 MHz (CDCl3) ppm 8.24 (2, d, J=9 Hz, 1/2 aromatic AB pNB), 7.61 (2, d, J=9, 1/2 pNB AB), 7.28 (5, s, phenyl), 5.54 (2, m's, C6 --C5 --H's), 5.40 (2, br s, pNB methylene), 4.91 (1, s, C3 --H), 4.27 1, d, J=12, 1/2 C2 --CHHO AB), 4.08 (1, d, J=12, 1/2 C2 --methylene AB), 3.12 ##STR73## 2.12 (3, s, acetyl), and 1.41 (3, s, C2 --CH3).

Workup

  1. concentrationThe light orange solution was concentrated in vacuo to a foam which
  2. customwas chromatographed on silica gel (500 g) with methylene chloride
  3. washTwo major bands were eluted
  4. customobtained in 45% yield (2.56 g) as an off-white foam

Sources & evidence

ORD record
ord-0afdc3ad1115418992f71dc165b57d20
Source dataset
uspto-grants-1983_10
Patent number
US04407755

Reaction notes

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