Objective: To synthesize roxatidine acetate and its salt. Methods: Using orthogonal test method, reactant ratio was made. Roxatidine acetate was synthesized. Excel was used to synthesize data and make statistics chart. Result: Salt of roxatidine ac?etate was synthesized in four steps with overall yield of 28?8%. Conclusion: The process is moderate and simple and the production cost is low.

BACKGROUND:Up to now,there is no literature on the relationship between blood laboratory tests and the course of nontraumatic osteonecrosis of femoral head in different stages.It is necessary to further explore and analyze so as to better clarify the influencing factors of nontraumatic osteonecrosis of femoral head. OBJECTIVE:To analyze the relationship between blood laboratory indicators and the course of nontraumatic osteonecrosis of the femoral head by the Association Research Circulation Osseous(ARCO),thus exploring the influencing factors of blood laboratory indicators on the course of nontraumatic osteonecrosis of the femoral head. METHODS:This study used a retrospective study design.A total of 2 103 patients with osteonecrosis of the femoral head were retrieved from Wangjing Hospital of China Academy of Chinese Medical Sciences database,and 1 075 patients with nontraumatic osteonecrosis of the femoral head were ultimately included based on inclusion and exclusion criteria.Patient age,gender,body mass index,and blood laboratory test results were collected.Blood laboratory tests included low-density lipoprotein,total cholesterol,triglycerides,high-density lipoprotein,apolipoprotein β,apolipoprotein α1,uric acid,total protein quantitative,alkaline phosphatase,activated partial thromboplastin time,prothrombin time,prothrombin time International Normalized Ratio,prothrombin time activity,fibrinogen quantitative,coagulation time of thrombin,D-dimer,total iron binding capacity,and platelet count.The indicators of patients with different age groups and different ARCO stages were compared,and multiple Logistic regression analysis was applied to explore the influencing factors of ARCO stages in osteonecrosis of the femoral head. RESULTS AND CONCLUSION:(1)There were statistical differences in total cholesterol,uric acid,prothrombin time,prothrombin time International Normalized Ratio,and D-dimer among ARCO stages in the young group(P<0.05).Among young patients in ARCO stage II,total cholesterol levels were higher than those in ARCO stage III(P<0.05).Uric acid levels in ARCO stage IV were higher than those in ARCO stage II and III(P<0.05).Prothrombin time and prothrombin time International Normalized Ratio were shorter in ARCO stage IV and II than in ARCO stage III(P<0.05).D-dimer levels were higher in ARCO stage III and IV than in ARCO stage II(P<0.05).(2)There were statistically significant differences in high-density lipoprotein,coagulation time of thrombin,and D-dimer among ARCO stages in the middle-aged group(P<0.05).Among middle-aged patients in ARCO stage IV,high-density lipoprotein levels were higher than those in ARCO stages II and III(P<0.05).Coagulation time of thrombin was shorter in ARCO stage IV than in ARCO stage III(P<0.05).D-dimer levels were higher in ARCO stages IV than in ARCO stages II and III(P<0.05).(3)The uric acid,activated partial thromboplastin time,D-dimer,and platelet count in the elderly group showed statistically significant differences(P<0.05).The uric acid level in ARCO stage IV was higher than that in ARCO stage II and III patients in the elderly group(P<0.05),while the activated prothrombin time in ARCO stage II patients was shorter than that in ARCO stage III patients in the elderly group(P<0.05).The D-dimer level in ARCO stage III and IV patients was higher than that in ARCO stage II patients in the elderly group(P<0.05).The platelet count in ARCO stage IV was lower than that in ARCO stage III patients in the elderly group(P<0.05).(4)Multiple logistic regression analysis showed that total cholesterol and platelet count may be protective factors for course of nontraumatic osteonecrosis of the femoral head,while D-dimer,uric acid,overweight,and young and middle age may be risk factors for course of nontraumatic osteonecrosis of the femoral head.(5)It is indicated that total cholesterol,high-density lipoprotein,uric acid,prothrombin time,prothrombin time International Normalized Ratio,and D-dimer are statistically significant among patients with different ARCO stages.Total cholesterol and platelet count may be protective factors for the course of nontraumatic osteonecrosis of the femoral head,while D-dimer,uric acid,overweight,and middle-aged and young age groups may be hazard factors for the course of nontraumatic osteonecrosis of the femoral head.