Chloride → 1H-1lambda~6~,2-Benzothiazole-1,1-dione

참여 물질

반응 단계

For longer side chains, the rearrangement is performed with n-BuLi (ca 1.6 M in hexane) in THF at −78° C. as above, followed by addition of a cosolvent such as DMPU and reaction with O-protected 1-bromo-alcohols or α-chloro-ω-iodoalkane (e.g. 1-bromo-n-tetrahydro-pyaranyloxyalkane) to yield the O-protected compounds 9b or the chloro compound 9c (step i). O-protected compounds 9b can be deprotected to the corresponding alkynol 9a (in MeOH at 50–60° C., in the presence of catalytic amount of pyridinium toluene-4-sulfonate). Alcohol 9a can be reacted with Huenig's base/trifluoromethane sulfonic acid anhydride at −15° C. in CH2Cl2 (in situ generation of the corresponding triflate) followed by treatment with Huenig's base and the corresponding amine NHA1A2 at −15° C. to RT to give amine 5. Alternatively, mesylation of alcohol 9a with methanesulfonylchloride, pyridine and DMAP in CH2Cl2 at 0° C. to RT gives mesylate 10. Conversion of the mesylate 10 or the chloride 9c (or the in situ generated iodide) to the amine 5 can be accomplished with an excess of the corresponding amine NHA1A2 in DMA at RT or as described above (step 1).

출처 및 근거