Reaction SMILES: [C:1]([NH:20][C:21]1[S:22][CH:23]=[C:24](/[C:26](=[N:30]/[O:31][CH2:32][C:33]2[N:34]=[C:35]([NH:38][C:39]([C:52]3[CH:57]=[CH:56][CH:55]=[CH:54][CH:53]=3)([C:46]3[CH:51]=[CH:50][CH:49]=[CH:48][CH:47]=3)[C:40]3[CH:45]=[CH:44][CH:43]=[CH:42][CH:41]=3)[S:36][CH:37]=2)/[C:27]([OH:29])=O)[N:25]=1)([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.P(Cl)(Cl)(Cl)(Cl)Cl.[CH:64]([O:77][C:78]([C:80]1[N:85]2[C:86](=[O:89])[CH:87]([NH2:88])[C@H:84]2[S:83][CH2:82][C:81]=1[CH2:90][S:91][C:92]1[N:96]([CH3:97])[N:95]=[N:94][N:93]=1)=[O:79])([C:71]1[CH:76]=[CH:75][CH:74]=[CH:73][CH:72]=1)[C:65]1[CH:70]=[CH:69][CH:68]=[CH:67][CH:66]=1.Cl>ClCCl.N1C=CC=CC=1>[CH:64]([O:77][C:78]([C:80]1[N:85]2[C:86](=[O:89])[CH:87]([NH:88][C:27](=[O:29])/[C:26](/[C:24]3[N:25]=[C:21]([NH:20][C:1]([C:8]4[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=4)([C:14]4[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=4)[C:2]4[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=4)[S:22][CH:23]=3)=[N:30]\[O:31][CH2:32][C:33]3[N:34]=[C:35]([NH:38][C:39]([C:52]4[CH:53]=[CH:54][CH:55]=[CH:56][CH:57]=4)([C:40]4[CH:41]=[CH:42][CH:43]=[CH:44][CH:45]=4)[C:46]4[CH:51]=[CH:50][CH:49]=[CH:48][CH:47]=4)[S:36][CH:37]=3)[C@H:84]2[S:83][CH2:82][C:81]=1[CH2:90][S:91][C:92]1[N:96]([CH3:97])[N:95]=[N:94][N:93]=1)=[O:79])([C:71]1[CH:72]=[CH:73][CH:74]=[CH:75][CH:76]=1)[C:65]1[CH:70]=[CH:69][CH:68]=[CH:67][CH:66]=1
Reactant: O=C(O)/C(=N\OCc1csc(NC(c2ccccc2)(c2ccccc2)c2ccccc2)n1)c1csc(NC(c2ccccc2)(c2ccccc2)c2ccccc2)n1
Reactant: Cn1nnnc1SCC1=C(C(=O)OC(c2ccccc2)c2ccccc2)N2C(=O)C(N)[C@H]2SC1
Agent: Cl
Agent: ClP(Cl)(Cl)(Cl)Cl
Solvent: c1ccncc1
Solvent: ClCCl
Product: Cn1nnnc1SCC1=C(C(=O)OC(c2ccccc2)c2ccccc2)N2C(=O)C(NC(=O)/C(=N\OCc3csc(NC(c4ccccc4)(c4ccccc4)c4ccccc4)n3)c3csc(NC(c4ccccc4)(c4ccccc4)c4ccccc4)n3)[C@H]2SC1
Temperature: -35 °C
Reaction time: 0.25 h
Yield: 63.4 %

Procedure:
In 6 ml of dichloromethane was suspended 500 mg of (Z)-α-(2-tritylamino-4-thiazolyl)-α-[(2-tritylamino-4-thiazolyl)methoxyimino]acetic acid and after cooling the suspension to 3°-4° C. and adding thereto 133 mg of phosphorus pentachloride, the mixture was stirred for 15 minutes at 3°-4° C. On the other hand, 316 mg of 7-amino-3-(1-methyl-5-tetrazolyl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester was dissolved in 6 ml of dichloromethane. After cooling the solution to -35° C. and adding 500 mg of pyridine, the foregoing dichloromethane solution containing acid chloride was added dropwise to the solution. Thereafter, the mixture was stirred for 15 minutes at -20° C. to -30° C., 20 ml of ice water was added to the reaction solution, the pH of the solution was adjusted to 1-2 with 1N hydrochloric acid, and the dichloromethane layer thus formed was separated. The dichloromethane layer was washed with water, dried (over anhydrous magnesium sulfate), and concentrated. The residue thus formed was applied to column chromatography and it was eluted with benzene and then with a mixture of benzene and ethyl acetate (5:1) to provide 510 mg of (Z)-7-{α-(2-tritylamino-4-thiazolyl)-α-[(2-tritylamino-4-thiazolyl)methoxyimino]acetamido}-3-[(1-methyl-5-tetrazolyl)thiomethyl]-3-cephem-4-carboxylic acid benzhydryl ester.