HCID 88819542, compound → HCID 70636605, compound
Reaction equation
[CH3:1][Li].[C:3]([NH:6][CH:7]1[C:29](=[O:30])[N:9]2[C:10]([C:17]([O:19][CH2:20][C:21]3[CH:26]=[CH:25][C:24]([O:27][CH3:28])=[CH:23][CH:22]=3)=[O:18])=[C:11]([N:14]=[C:15]=[O:16])[CH2:12][S:13][C@H:8]12)(=[O:5])[CH3:4]>>[C:3]([NH:6][CH:7]1[C:29](=[O:30])[N:9]2[C:10]([C:17]([O:19][CH2:20][C:21]3[CH:22]=[CH:23][C:24]([O:27][CH3:28])=[CH:25][CH:26]=3)=[O:18])=[C:11]([NH:14][C:15](=[O:16])[CH3:1])[CH2:12][S:13][C@H:8]12)(=[O:5])[CH3:4]Participants
Procedure
As in the case of the aforedescribed reaction of amines with the 3-isocyanato-2-cephems, the reaction of such isocyanates with carbanionic reagents is accompanied by the rearrangement of the double bond in the cephem ring. Thus, benzhydryl 7-benzyloxycarbonylamino-3-isocyanato-2-cephem-4-carboxylate reacts with 1.1 equivalents of sodium diethylmalonate in tetrahydrofuran at -20° C. over a 5 minute period, to provide after hydrolysis with about 3 equivalents of 1N.HCl, benzhydryl 7 -benzyloxycarbonylamino-3-di(ethoxycarbonyl)acetamido-3-cephem-4-carboxylate. Likewise tert-butyl 7-(3-chlorophenylacetamido)-3-isocyanato-2-cephem-4carboxylate reacts with about 1.1 equivalents of isopropylmagnesium bromide in tetrahydrofuran at about --70° C. over a 30 minute period to give, upon acid hydrolysis, tert-butyl 7-(2-chlorophenylacetamido)-3-(2-methyl-propionamido)-3-cephem-4-carboxylate. The reaction of methyllithium with 4-methoxybenzyl 7-acetamido-3-isocyanato-3-cephem-4-carboxylate under similar conditions yields 4-methoxybenzyl 7-acetamido-3-acetamido-3-cephem-4-carboxylate.
Sources & evidence
- ORD record
- ord-0ac256f1e4f54d5d873d6b610c4f20ba
- Source dataset
- uspto-grants-1977_01
- Patent number
- US04001226
Reaction notes
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