{
    "pdf_info": [
        {
            "para_blocks": [
                {
                    "bbox": [
                        14,
                        0,
                        1298,
                        216
                    ],
                    "type": "text",
                    "angle": 0,
                    "lines": [
                        {
                            "bbox": [
                                14,
                                0,
                                1298,
                                216
                            ],
                            "spans": [
                                {
                                    "bbox": [
                                        14,
                                        0,
                                        1298,
                                        216
                                    ],
                                    "type": "text",
                                    "content": "首先是羰基氧原子接受质子, 而后生成烯醇。决定反应速率的步骤是生成烯醇的一步, 生成烯醇后, 卤素作为亲电试剂与烯醇的双键发生亲电加成, 生成 "
                                },
                                {
                                    "bbox": [
                                        14,
                                        0,
                                        1298,
                                        216
                                    ],
                                    "type": "inline_equation",
                                    "content": "\\alpha"
                                },
                                {
                                    "bbox": [
                                        14,
                                        0,
                                        1298,
                                        216
                                    ],
                                    "type": "text",
                                    "content": "-卤代羰基化合物和卤化氢, 所以酸催化常常是自催化。例如治疗支气管炎、喘息性支气管炎药物氯丙那林(Clorprenaline)中间体 "
                                },
                                {
                                    "bbox": [
                                        14,
                                        0,
                                        1298,
                                        216
                                    ],
                                    "type": "inline_equation",
                                    "content": "\\alpha"
                                },
                                {
                                    "bbox": [
                                        14,
                                        0,
                                        1298,
                                        216
                                    ],
                                    "type": "text",
                                    "content": "-溴代邻氯苯乙酮(1)的制备 (张宝丰. 中国医药工业杂志, 1989, 20:33):"
                                }
                            ]
                        }
                    ],
                    "index": 0
                },
                {
                    "type": "image",
                    "bbox": [
                        59,
                        241,
                        691,
                        464
                    ],
                    "blocks": [
                        {
                            "bbox": [
                                59,
                                241,
                                691,
                                464
                            ],
                            "lines": [
                                {
                                    "bbox": [
                                        59,
                                        241,
                                        691,
                                        464
                                    ],
                                    "spans": [
                                        {
                                            "bbox": [
                                                59,
                                                241,
                                                691,
                                                464
                                            ],
                                            "type": "image",
                                            "image_path": "13d3f822a19e58284df7e8f6375844713ec35907bdd2e920ebf752ecfc2c1b95.jpg"
                                        }
                                    ]
                                }
                            ],
                            "index": 1,
                            "angle": 0,
                            "type": "image_body"
                        }
                    ],
                    "index": 1
                },
                {
                    "bbox": [
                        19,
                        556,
                        1290,
                        769
                    ],
                    "type": "text",
                    "angle": 0,
                    "lines": [
                        {
                            "bbox": [
                                19,
                                556,
                                1290,
                                769
                            ],
                            "spans": [
                                {
                                    "bbox": [
                                        19,
                                        556,
                                        1290,
                                        769
                                    ],
                                    "type": "text",
                                    "content": "反应时经常有一个诱导期,因为反应开始时烯醇化速率较慢。随着反应的进行,卤化氢浓度增大,烯醇化速率加快,反应也相应加快。反应初期,可加入少量氢卤酸以缩短诱导期,光照也常起到明显的催化效果。Lewis酸对某些反应有催化作用,例如苯乙酮的溴化,在催化量的三氯化铝存在下生成 "
                                },
                                {
                                    "bbox": [
                                        19,
                                        556,
                                        1290,
                                        769
                                    ],
                                    "type": "inline_equation",
                                    "content": "\\alpha"
                                },
                                {
                                    "bbox": [
                                        19,
                                        556,
                                        1290,
                                        769
                                    ],
                                    "type": "text",
                                    "content": "-溴代苯乙酮,而三氯化铝过量时生成间-溴苯乙酮。"
                                }
                            ]
                        }
                    ],
                    "index": 2
                },
                {
                    "type": "image",
                    "bbox": [
                        59,
                        798,
                        950,
                        1072
                    ],
                    "blocks": [
                        {
                            "bbox": [
                                59,
                                798,
                                950,
                                1072
                            ],
                            "lines": [
                                {
                                    "bbox": [
                                        59,
                                        798,
                                        950,
                                        1072
                                    ],
                                    "spans": [
                                        {
                                            "bbox": [
                                                59,
                                                798,
                                                950,
                                                1072
                                            ],
                                            "type": "image",
                                            "image_path": "b1459176fc74696f7ac62ec4c74a5593cc9087862c96fbcc27be5e98a3933f39.jpg"
                                        }
                                    ]
                                }
                            ],
                            "index": 3,
                            "angle": 0,
                            "type": "image_body"
                        }
                    ],
                    "index": 3
                }
            ],
            "discarded_blocks": [],
            "page_size": [
                1300,
                1076
            ],
            "page_idx": 0
        }
    ],
    "_backend": "vlm",
    "_version_name": "2.6.3"
}