Acetyl chloride → Methyl cholate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Preparation of the starting compounds of the formula III using the example of methyl cholanate (Fieset et al., J. Am. Chem. Soc. 74, 1952, 3309) ##STR6## 450 ml of acetyl chloride are slowly added dropwise to 4.5 l of methanol, while cooling with ice, such that the temperature does not exceed 10° to 15° C. After the addition, the mixture is subsequently stirred at about 10° C. for a further 15 minutes. 600 g (1.47 mol) of cholic acid are then introduced at about 5° C. The ice-bath is removed, and after a further hour, while stirring, the reaction is ended. The reaction mixture is slowly added to 12 l of water. The mixture is stirred for a further 2 hours and then filtered with suction, and the residue is rinsed with 3 l of water. The crystalline substance is dried in vacuo at 50° C. 610 g (98%) of methyl cholate (melting point 154° C.) are obtained.

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