摘要:
Provided is a novel preparation method of (Z)-7-chloro-((S)-2,2-dimethylcyclopropanecarboxamido)-2-heptenoic acid represented by the following formula (1), a key intermediate of cilastatin used as a supplement to imipenem. The novel preparation method of the invention produces a pure (Z)-7-chloro-((S)-2,2-dimethylcyclopropanecarboxamido)-2-heptenoic acid, a key intermediate of cilastatin, by selective hydrolysis of E isomers.
摘要:
A noise reduction device has a side branch silencer. The side branch silencer is formed within a discharge valve assembly which includes is divided into a discharge muffler, a gasket, a discharge valve piece and a valve plate. The side branch silencer is provided with a cutout formed through the gasket to communicate with a discharge passage formed through the gasket. The cutout is blocked vertically by both a lower surface of a muffler plate of the discharge muffler and an upper surface of the discharge valve piece.