5-chloro-thiophene-2-carboxylic acid (R)-pyrrolidin-3-ylamide hydrochloride   、                                                                                      
2-溴丙酸乙酯                                                                                                                                                                                                                                                                                                          以to give 2-{(R)-3-[(5-chloro-thiophene-2-carbonyl)-amino]-pyrrolidin-1-yl}-propionic acid ethyl ester的产率得到2-{(R)-3-[(5-chloro-thiophene-2-carbonyl)-amino]-pyrrolidin-1-yl}-propionic acid ethyl ester