Thionyl Chloride → 2-(2-Formamidothiazol-4-yl)-2-methoxyiminoacetyl chloride

HRID 621305Notes

Reaction equation

[CH:1]([NH:3][C:4]1[S:5][CH:6]=[C:7]([C:9](=[N:13][O:14][CH3:15])[C:10](O)=[O:11])[N:8]=1)=[O:2].S(Cl)([Cl:18])=O>CN(C)C=O>[CH:1]([NH:3][C:4]1[S:5][CH:6]=[C:7]([C:9](=[N:13][O:14][CH3:15])[C:10]([Cl:18])=[O:11])[N:8]=1)=[O:2]

Participants

Conditions

Temperature: 60 °C

Procedure

N,N-Dimethylformamide (3 drops) was added to a suspension of 2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetic acid (syn isomer, 23 g.) in thionyl chloride (230 ml), and stirred at 60° C. for 5 minutes. After concentrating the solution in vacuo, benzene was added to the residue. The presipitates were collected by filtration, washed with benzene (30 ml.) three times and diethyl ether in turn to give 2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetyl chloride (anti isomer, 18 g.). On the other hand, trimethylsilylacetamide (46 g.) was added to a suspension of 4-nitro benzyl 7-amino-3-cephem-4-carboxylate (16.8 g.) in methylene chloride (168 ml.), and stirred at 40° C. for an hour. To the suspension was gradually added 2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetyl chloride (anti isomer, 13.6 g.) at -5° to 0° C., and stirred at the same temperature for an hour. Water (150 ml.) was added to the resultant solution and stirred for 15 minutes. The recipitates were collected by filtration, washed with water and dried over phosphorus pentoxide under reduced pressure to give 4-nitrobenzyl 7-[2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylate (anti isomer, 25.7 g.).

Workup

concentrationAfter concentrating the solution in vacuo, benzene
additionwas added to the residue
filtrationThe presipitates were collected by filtration
washwashed with benzene (30 ml.) three times and diethyl ether in turn

Sources & evidence

ORD record: ord-e7235ef600df45d5b714701114ab3723
Source dataset: uspto-grants-1989_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04822888

Reaction notes

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