Reaktion #307917

Reaktionsgleichung

2-acetylamino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid

N,N-dimethylformamide

diphenylphosphoryl azide

hydrochloric acid

N,N-dimethylformamide

triethylamine

→

white solid

(2-Acetylamino-4,5,6,7-tetrahydro-benzothiazol-6-yl)-carbamic acid methyl ester hydrochloride

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 500 ml reactor equipped with mechanical stirrer
2. 2
   workup.ADDITIONis dropped
3. 3
   workup.ADDITIONThe reaction mixture gradually solubilizes during the addition until complete dissolution
4. 4
   workup.WAITThe mixture is left
5. 5
   Temperaturto cool
6. 6
   Extraktionextracted twice with 100 ml of methylene chloride
7. 7
   EinengenThe aqueous phase is concentrated to a residue that
8. 8
   Sonstigeis crystallized from i-propanol-water

Vorschrift

A 500 ml reactor equipped with mechanical stirrer, thermometer and condenser is loaded with 5 g of 2-acetylamino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid [(I), R=—NH—CO—CH3] suspended in 80 ml of N,N-dimethylformamide; then 2.32 g of triethylamine are added. A solution consisting of 6.3 g of diphenylphosphoryl azide (DPPA) dissolved in 7 ml N,N-dimethylformamide is dropped therein in 2 hours. The reaction mixture gradually solubilizes during the addition until complete dissolution. After 6 hours the reaction solution is dropped in 1 liter of a methanol solution containing 8 ml of 37% hydrochloric acid at 60° C. The mixture is left to cool, then extracted twice with 100 ml of methylene chloride, discarding the organic phase. The aqueous phase is concentrated to a residue that is crystallized from i-propanol-water to obtain 3.6 g of a white solid.

Quelle