反应详情

13.2 g of diethyl azodicarboxylate were added dropwise to a solution of 20.7 g of triphenylphosphine in 300 ml of benzene, whilst ice-cooling. The mixture was then stirred at room temperature for 30 minutes, after which 35.0 g of 5-(4-hydroxybenzyl)-3-triphenylmethylthiazolidine-2,4-dione [prepared as described in Preparation 11] were added. The mixture was then stirred at room temperature for one hour, after which 13.2 g of (R)-2-t-butoxycarbonylamino-1-propanol were added to the mixture and the mixture was allowed to stand overnight at the same temperature. 40.9 g of triphenylphosphine, 23.68 ml of diethyl azodicarboxylate and 33 g of (R)-2-t-butoxycarbonylamino-1-propanol were then added, in turn and in 3 or 4 portions, to the mixture, and the mixture was stirred for 2 days. At the end of this time, the reaction mixture was freed from benzene by distillation under reduced pressure. The residue was then purified by column chromatography through silica gel, using a 1:3 by volume mixture of ethyl acetate and hexane as the eluent, to give 30.0 g of 5-{4-[2(R)-t-butoxycarbonylamino-1-propoxy]benzyl}-3-triphenylmethylthiazolidine-2,4-dione, melting at between 153° C. and 157° C.

1. temperaturecooling
2. stirringThe mixture was then stirred at room temperature for one hour
3. waitto stand overnight at the same temperature
4. stirringthe mixture was stirred for 2 days
5. distillationAt the end of this time, the reaction mixture was freed from benzene by distillation under reduced pressure
6. customThe residue was then purified by column chromatography through silica gel
7. additionby volume mixture of ethyl acetate and hexane as the eluent