Isobutyl chloroformate → 3-[[5-(Azidomethyl)tetrahydro-3-furanyl]thio]-4-methyl-6-[1-[[(2-methylpropoxy)carbonyl]oxy]ethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid (4-nitrophenyl)methyl ester

HRID 1290412Notes

Reaction equation

[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([CH2:10][O:11][C:12]([C:14]2[N:15]3[CH:18]([CH:19]([CH3:31])[C:20]=2[S:21][CH:22]2[CH2:26][CH:25]([CH2:27][N:28]=[N+:29]=[N-:30])[O:24][CH2:23]2)[CH:17]([CH:32]([OH:34])[CH3:33])[C:16]3=[O:35])=[O:13])=[CH:6][CH:5]=1)([O-:3])=[O:2].Cl[C:37]([O:39][CH2:40][CH:41]([CH3:43])[CH3:42])=[O:38].C[Si]([N-][Si](C)(C)C)(C)C.[Li+]>O1CCCC1>[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([CH2:10][O:11][C:12]([C:14]2[N:15]3[CH:18]([CH:19]([CH3:31])[C:20]=2[S:21][CH:22]2[CH2:26][CH:25]([CH2:27][N:28]=[N+:29]=[N-:30])[O:24][CH2:23]2)[CH:17]([CH:32]([O:34][C:37]([O:39][CH2:40][CH:41]([CH3:43])[CH3:42])=[O:38])[CH3:33])[C:16]3=[O:35])=[O:13])=[CH:6][CH:5]=1)([O-:3])=[O:2]

Participants

Conditions

Temperature: -78 °C

Procedure

Using anhydrous conditions, 1.25 g of product from Example 45 in 27 ml of anhydrous tetrahydrofuran, is cooled to -78° C. under argon. 0.325 ml of isobutyl chloroformate is added, followed by 2.7 ml of lithium bis(trimethylsilyl)amide. The reaction mixture is stirred at -78° C. for 1 hour, followed by stirring at -55° C. for another hour and then concentrated in vacuo. The residue is purified by chromatography (Silica Gel: 50% ethyl acetate/hexane) to give 1.22 g of the desired product.

Workup

stirringby stirring at -55° C. for another hour
concentrationconcentrated in vacuo
customThe residue is purified by chromatography (Silica Gel: 50% ethyl acetate/hexane)

Sources & evidence

ORD record: ord-27f0b3e3e0c94ac89d8edda82af489d5
Source dataset: uspto-grants-1998_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05750735

Reaction notes

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