An expeditious and efficient bromomethylation of thiols: enabling bromomethyl sulfides as useful building blocks
作者:Carolina Silva-Cuevas、Ehecatl Paleo、David F. León-Rayo、J. Armando Lujan-Montelongo
DOI:10.1039/c8ra04002h
日期:——
A new method for the bromomethylation of thiols using paraformaldehyde and HBr/AcOH, minimizes the generation of toxic byproducts. Synthetic utility of α-bromomethyl sulfides was demonstrated through umpolung and free radical chemistry.
Methlenediphosphonic acid derivatives, and antirheumatic pharmaceutical
申请人:Sanofi
公开号:US04876247A1
公开(公告)日:1989-10-24
The invention relates to methylenediphosphonic acid derivatives of the formula: ##STR1## in which: R.sub.1 represents: a C.sub.1 -C.sub.6 alkyl group, a C.sub.5 -C.sub.7 cycloalkyl group, a phenyl group optionally monosubstituted or polysubstituted by a halogen, a C.sub.1 -C.sub.6 alkyl group or a trifluoromethyl group, or a 5-membered or 6-membered heterocycle containing 1 or 2 heteroatoms chosen from nitrogen and sulfur, Alk denotes a linear or branched C.sub.1 -C.sub.6 alkylene group, R.sub.2 represents hydrogen, a C.sub.1 -C.sub.6 alkyl group or a --CONH.sub.2 group, R.sub.3 represents hydrogen, a C.sub.1 -C.sub.6 alkyl group, a benzyl group or a phenyl group optionally substituted by chlorine or methyl groups; or alternatively R.sub.2 and R.sub.3, taken together, represent a (CH.sub.2).sub.m group, in which m=4 or 5, and finally n represents 0 or the integer 1 or 2. These derivatives possess antirheumatic properties.