Diethyl Ether → Methyl 2-aminobenzo[d]thiazole-7-carboxylate

HRID 611778

Reaktionsgleichung

Reaktionsgleichung von HRID 611778
[NH:1]([C:5]1[CH:6]=[C:7]([CH:12]=[CH:13][CH:14]=1)[C:8]([O:10][CH3:11])=[O:9])[C:2]([NH2:4])=[S:3].BrBr.C(OCC)C>ClC1C=CC=CC=1>[NH2:4][C:2]1[S:3][C:6]2[C:7]([C:8]([O:10][CH3:11])=[O:9])=[CH:12][CH:13]=[CH:14][C:5]=2[N:1]=1

Komponenten

5

Versuchsvorschrift

8.4 g of methyl 3-thioureido-benzoate are suspended in 120 ml of chlorobenzene, 2.2 ml of bromine in 30 ml of chlorobenzene are added at 0° C. in the course of 1 hour, while stirring as thoroughly as possible, and the mixture is then stirred to room temperature. It is then kept at 70° C. for 4 hours and subsequently cooled, a little diethyl ether is added and the precipitate is filtered off, mixed thoroughly with 70 ml of aqueous sodium bicarbonate solution, filtered off again and washed with water. 7.7 g (88%) of crude product of melting point 231-232° C. result. HPLC analysis shows a content of more than 83% of the pure title compound, in addition to 8-18% of isomeric methyl 2-amino-benzothiazole-5-carboxylate. Suspension in and brief heating at 70° C. with ethyl acetate, cooling to 30° C. and filtration give the pure title compound of melting point >250° C. If the reaction is carried out in acetic acid (instead of in chlorobenzene), the content of the undesired isomeric methyl 2-amino-benzothiazole-5-carboxylate is only about 5%.

Aufarbeitung

  1. stirringis then stirred to room temperature
  2. temperaturesubsequently cooled
  3. filtrationthe precipitate is filtered off
  4. additionmixed thoroughly with 70 ml of aqueous sodium bicarbonate solution
  5. filtrationfiltered off again
  6. washwashed with water
  7. custom7.7 g (88%) of crude product of melting point 231-232° C. result

Quellen und Nachweise

ORD-Eintrag
ord-19fa00906ed84435a0b61ac3a23e8fd9
Quelldatensatz
uspto-grants-1999_12
Patentnummer
US06002013

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