Hydrochloric Acid → 7alpha-Chloro-3-methyl-3-cephem-4-carboxylic acid

HRID 257801

Reaction equation

[CH3:1][C:2]1[CH2:11][S:10][C@@H:5]2[C@H:6](N)[C:7](=[O:8])[N:4]2[C:3]=1[C:12]([OH:14])=[O:13].C(O)C.[ClH:18].N([O-])=O.[Na+]>[Cl-].[Na+].O.O>[Cl:18][C@H:6]1[C:7](=[O:8])[N:4]2[C:3]([C:12]([OH:14])=[O:13])=[C:2]([CH3:1])[CH2:11][S:10][C@H:5]12

Participants

Conditions

Temperature: 5 °C

Procedure

A mixture of 7-ADCA (25 g, 0.117 mol), ethanol (700 ml), water (163 ml) and concentrated hydrochloric acid (163 ml) was cooled to 5° C. Sodium nitrite (11.5 g, 0.167 mol) was added in small portions over 25 minutes and the mixture was stirred for 3.5 hours at 0°-5° C.; 300 ml of brine was added and the reaction mixture was extracted with methylene chloride. The organic extract was washed with water, brine, dried over sodium sulfate and concentrated (16.1 g, 58.9%). This crude acid was directly used for the next step without further purification.

Workup

extractionthe reaction mixture was extracted with methylene chloride
extractionThe organic extract
washwas washed with water, brine
dry with materialdried over sodium sulfate
concentrationconcentrated (16.1 g, 58.9%)
customThis crude acid was directly used for the next step without further purification

Sources & evidence

ORD record: ord-4f66a560b4d744959a2551b9024d02ec
Source dataset: uspto-grants-1993_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05264430

Linked notes

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