Sodium Iodide → 3-Iodo-2-benzofuran-1(3H)-one

HRID 1764358Notes

Reaction equation

HRID 1764358 reaction equation
C(#N)C.[I-:4].[Na+].Br[CH:7]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:9](=[O:10])[O:8]1.CC(OCC1CS[C@@H]2[C@H](NC(CC3SC=CC=3)=O)C(=O)N2C=1C(O)=O)=O>CS(C)=O>[I:4][CH:7]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:9](=[O:10])[O:8]1

Participants

6

Reactant 4

HCID 5238Sodium IodideHCID 6024CephalothinHCID 6342AcetonitrileHCID 962181(3H)-Isobenzofuranone, 3-bromo-

Product 1

HCID 130658183-Iodo-2-benzofuran-1(3H)-one

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

Iodophthalide was prepared immediately prior to use by mixing acetonitrile solutions of sodium iodide (1.5mmole) and bromophthalide (1.5mmole) and stirring for 3 minutes. This solution was filtered (to remove precipitated sodium bromide) into an ice cooled DMSO solution of cephalothin (1mmole), stirred 10 minutes and poured into ice water to precipitate the required ester. Yield of crude, neutral product after work up -- 90%. TLC and NMR indicate >90% ceph-3-em ester. δ (CDCl3 /trace DMSO) = 2.08 (d, 3H, --OCOCH3), 3.61 (broad s, 2H, C2--H), 3.88 (s, 2H, α-CH2), 4.6 - 5.4 (ABq + d, 3H, --CH2O-- + C6), 5.6 - 6.0 (m, 1H, C7) 6.9 - 7.4 (d, + t, 3H, thienyl aromatics), 7.5 - 8.2 (m, ca. 5H, phthalidyl aromatics and --OCHO--), 8.2 - 8.6 (2d, 1H, amide N-H). νmax (CHCl3) 3370, 2960, 1793, 1743, 1682, 1505, 1230, 982cm-1 ; λmax (EtOH) 275nm (ε, 7000)

Workup

  1. filtrationThis solution was filtered
  2. custom(to remove precipitated sodium bromide) into an ice
  3. stirringstirred 10 minutes
  4. customto precipitate the required ester

Sources & evidence

ORD record
ord-bf3fb3526225454f9c59fd914b6d8713
Source dataset
uspto-grants-1978_09
Patent number
US04115646

Reaction notes

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