2-chloro-9-cyclopentyl-7,7-difluoro-5-methyl-5,7,8,9-tetrahydro-6H-pyrimido[4,5-b][1,4]diazepin-6-one   、                                                                                      
对氨基苯甲酸                                                                                                                                                              在
                                                                                                                                                                                 
水                                                                                                                                  作用下,
                                                                                                                以
                                                                                         Ethanol water hydrochloric acid                                                                                  为溶剂,
                                                                                                                                                    反应 18.0h,
                                                                                                                以to give 0.11 g of 4-(9-cyclopentyl-7,7-difluoro-5-methyl-6-oxo-6,7,8,9-tetrahydro-5H-pyrimido[4,5-b][1,4]diazepin-2-ylamino)-benzoic acid (I-20)的产率得到4-(9-cyclopentyl-7,7-difluoro-5-methyl-6-oxo-6,7,8,9-tetrahydro-5H-pyrimido[4,5-b][1,4]diazepin-2-ylamino)-benzoic acid