Reaction SMILES: C1(N=C=NC2CCCCC2)CCCCC1.[NH2:16][CH:17]1[C:24](=[O:25])[N:23]2[CH:18]1[S:19](=[O:56])[CH2:20][C:21]([C:42]1[S:46][C:45]([NH:47][C:48](=[O:55])[C:49]3[CH:54]=[CH:53][CH:52]=[N:51][CH:50]=3)=[N:44][CH:43]=1)=[C:22]2[C:26]([O:28][CH:29]([C:36]1[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=1)[C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=1)=[O:27].[CH3:57][O:58][N:59]=[C:60]([C:64]1[N:65]=[C:66]([NH:69][C:70]([C:83]2[CH:88]=[CH:87][CH:86]=[CH:85][CH:84]=2)([C:77]2[CH:82]=[CH:81][CH:80]=[CH:79][CH:78]=2)[C:71]2[CH:76]=[CH:75][CH:74]=[CH:73][CH:72]=2)[S:67][CH:68]=1)[C:61](O)=[O:62].ON1C2C=CC=CC=2N=N1>CN(C)C=O>[CH:29]([O:28][C:26]([C:22]1[N:23]2[CH:18]([S:19](=[O:56])[CH2:20][C:21]=1[C:42]1[S:46][C:45]([NH:47][C:48](=[O:55])[C:49]3[CH:54]=[CH:53][CH:52]=[N:51][CH:50]=3)=[N:44][CH:43]=1)[CH:17]([NH:16][C:61](=[O:62])[C:60](=[N:59][O:58][CH3:57])[C:64]1[N:65]=[C:66]([NH:69][C:70]([C:77]3[CH:78]=[CH:79][CH:80]=[CH:81][CH:82]=3)([C:83]3[CH:88]=[CH:87][CH:86]=[CH:85][CH:84]=3)[C:71]3[CH:72]=[CH:73][CH:74]=[CH:75][CH:76]=3)[S:67][CH:68]=1)[C:24]2=[O:25])=[O:27])([C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=1)[C:36]1[CH:37]=[CH:38][CH:39]=[CH:40][CH:41]=1
Reactant: NC1C(=O)N2C(C(=O)OC(c3ccccc3)c3ccccc3)=C(c3cnc(NC(=O)c4cccnc4)s3)CS(=O)C12
Reactant: CON=C(C(=O)O)c1csc(NC(c2ccccc2)(c2ccccc2)c2ccccc2)n1
Agent: C(=NC1CCCCC1)=NC1CCCCC1
Agent: On1nnc2ccccc21
Solvent: CN(C)C=O
Product: CON=C(C(=O)NC1C(=O)N2C(C(=O)OC(c3ccccc3)c3ccccc3)=C(c3cnc(NC(=O)c4cccnc4)s3)CS(=O)C12)c1csc(NC(c2ccccc2)(c2ccccc2)c2ccccc2)n1
Reaction time: 64 h
Yield: 128.2 %

Procedure:
N,N'-Dicyclohexylcarbodiimide (1.24 g) is added to a solution, cooled to +5° C., of 7-amino-2-benzhydry-loxycarbonyl-8-oxo-3-(2-nicotinoylaminothiazol-5-yl)-5-thia- 1-azabicyclo[4.2.0]oct-2-ene 5-oxide (2.8g), the syn isomer of 2-methoxyimino-2-(2-tritylaminothiazol-4-yl)-acetic acid (2.66 g) and 1-hydroxybenzotriazole (0.82 g) in N,N-dimethylformamide (20 cc), and the reaction mixture is then stirred for 1 hour at +5° C. and then for 64 hours at 20° C; after filtration, the reaction mixture is diluted with chloroform (200 cc) and washed with a 5% strength solution of sodium bicarbonate (100 cc), water (100 cc) and then a saturated solution of sodium chloride (100 cc). After drying over magnesium sulphate, the organic phase is concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. to give the crude product (5 g). This crude product (10 g) is chromatographed on a column containing silica gel (0.2-0.06 mm) (250 cc), elution being carried out successively with a mixture of methylene chloride and ethyl acetate (75/25 by volume) (1 liter), then a mixture of methylene chloride and ethyl acetate (50/50 by volume) (1 liter) and then ethyl acetate (2 liters) and a mixture of ethyl acetate and methanol (80/20 by volume) (1 liter) and 100 cc fractions being collected. Fractions 19 to 33 are combined and concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. to give the syn isomer of 2-benzhydryLoxycarbonyl-7-[2-methoxyimino-2-(2-tritylaminothiazol-4-yl)-acetamido]-8-oxo-3-(2-nicotinoylaminothiazol-5-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene 5-oxide (6.2 g) in the form of an orange solid.