Cooperation of the Neutral and the Cationic Leaving Group Pathways in Acid-Catalyzed O-Benzylation of TriBOT.

The reaction profile of acid-catalyzed O-benzylation with 2,4,6-tris(benzyloxy)-1,3,5-triazine (TriBOT) was analyzed to study the reaction kinetics. The first-order kinetic constant for the formation of benzyl cation species from N-protonated TriBOT (neutral leaving group pathway) was estimated and compared with that of the model compound for TriBOT. Since rapid consumption of TriBOT in the late stage could not be explained solely by this pathway, cooperation of another reaction mechanism, the cationic leaving group pathway, was proposed to rationalize the rate acceleration.

Triazine-Based Cationic Leaving Group: Synergistic Driving Forces for Rapid Formation of Carbocation Species.

A new triazine-based cationic leaving group has been developed for the acid-catalyzed alkylation of O- and C-nucleophiles. There are two synergistic driving forces, namely, stable C═O bond formation and charge-charge repulsive effects, involved in the rapid generation of the carbocation species in the presence of trifluoromethanesulfonic acid (∼200 mol %). Considerable rate acceleration of benzylation, allylation, and p-nitrobenzylation was observed as compared to the reactions with less than 100 mol % of the acid catalyst. The triazine-based leaving group showed superior p-nitrobenzylation yield and stability in comparison to common leaving groups, trichloroacetimidate and bromide. A plausible reaction mechanism (the cationic leaving group pathway) was proposed on the basis of mechanistic and kinetic studies, NMR experiments, and calculations.

Study of O-Allylation Using Triazine-Based Reagents.

Acid-catalyzed allylating reagent 2,4,6-tris(allyloxy)-1,3,5-triazine (TriAT-allyl) and its substituted derivatives have been developed. The reaction of acid-, and alkali-labile alcohols with these reagents in the presence of a catalytic amount of trifluoromethanesulfonic acid (TfOH) afforded the corresponding allyl ethers in good yields. Reactions using these reagents with an unsymmetrically-substituted regioisometric allyl group suggested that a single isometric allylic cation species would be involved.

Study of the Reactivities of Acid-Catalyzed O-Benzylating Reagents Based on Structural Isomers of 1,3,5-Triazine.

We have demonstrated O-benzylating abilities of both 4,6-bis(benzyloxy)-1,3,5-triazin-2(1H)-one (DiBOT) and 6-(benzyloxy)-1,3,5-triazine-2,4(1H,3H)-dione (MonoBOT), which have been previously suggested as reaction intermediates of the acid-catalyzed benzylation of 2,4,6-tris(benzyloxy)-1,3,5-triazine (TriBOT). We studied the effect on the reactivity of acid-catalyzed O-benzylation caused by the isomeric core triazine structures in these compounds by carrying out a kinetic study and estimating relative basicities using model compounds. Since MonoBOT showed superior reactivity, 1,3,5-triazine-2,4(1H,3H)-dione is a promising core structure for acid-catalyzed alkylating reagents.

[A case of a metastatic spine tumor treated using a multidisciplinary approach].

A 5 0-year-old man who was a hepatitis B carrier was admitted with back pain due to bone metastasis of the 12 th thoracic vertebra(Th12)in November 2011. He had been diagnosed with liver cancer in January 2010 and underwent liver resection following hepatic arterial chemoembolization. He presented with performance status(PS)2 and a numeric rating scale(NRS) pain score of 8 out of 10 at the time of admission. We started the patient on radiation and drug therapy, but lower limb muscle weakness(manual muscle test[MMT]grade 4 out of 5, Frankel D classification)occurred on day 12 after admission. Therefore, we immediately consulted the orthopedician, and the patient underwent posterior decompression fixation on day 15, followed by radiation therapy and rehabilitation. Even after discontinuation of all analgesics, his pain level on the NRS was 0, and he had no progressive muscle weakness. We ensured long-term care as well as nursing home visits. The patient was discharged on day 61. We have a variety of criteria for the selection of surgery for spinal metastasis, including Tokuhashi, Tomita, and Katagiri scores. The patient's general condition and prognosis are important factors to consider when selecting surgical therapy. In the present case, because of selection of the appropriate treatment and timely cooperation with specialists, it was possible to effectively relieve symptoms and discharge the patient to home care.

[Three cases of lung cancer presenting with spinal cord paralysis as the initial manifestation-symptom control, nursing care, and coordination of home medical care].

Bone metastasis from lung cancer accounts for approximately 30% of all metastatic bone tumors. The median survival time of patients with stage IV lung cancer with bone metastases is 5.5 months and that of patients without bone metastases is 7.5 months. Here, we report 3 cases of spinal cord paralysis. All cases were assessed according to the Tokuhashi score. As the predicted survival time of these patients was < or = 6 months, we opted for conservative treatment. We administered chemotherapy and radiation therapy, ensured symptom control, provided nursing care (prevention of decubitus, position changing, defecation control, rehabilitation, and mental health care), and coordinated home medical care. Patient management was mediated by a multidisciplinary medical team. However, all 3 patients were unable to return home and died in the hospital within 1-2 months after the onset of spinal cord paralysis. Spinal metastases can be expected not only in patients with lung cancer but also in patients with other types of carcinomas. Early diagnosis and treatment and accurate prognosis prediction are essential. Rapid responses and cooperation from experts are required, and increased awareness regarding spinal metastases among health professionals is essential.