29134-54-1Relevant academic research and scientific papers
Prostaglandin conjugates for treating or preventing bone disease
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, (2008/06/13)
This invention relates to prostaglandin-bisphosphonate conjugates. These conjugates are effective for treating or preventing bone diseases such as osteoporosis. These conjugates simultaneously deliver a prostaglandin agent for increasing bone formation and a bisphosphonate agent for inhibiting bone resorption.
Benzyloxy(4-substituted benzyloxy)carbenes. Generation from oxadiazolines and fragmentation to radical pairs in solution
Merkley,Warkentin
, p. 942 - 949 (2007/10/03)
Thermolysis of 2,2-dibenzyloxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline in benzene at 110°C leads to dibenzyloxycarbene. The carbene was trapped with tert-butyl alcohol to afford dibenzyl-tert-butyl orthoformate. In the absence of a trapping agent for the carbene, it fragmented to benzyloxycarbonyl and benzyl radicals, as shown by trapping the latter with TEMPO. In the absence of both TEMPO and tert-butyl alcohol, the radicals were partitioned between coupling to benzyl phenylacetate and decarboxylation, with subsequent formation of bibenzyl. The preferred sense of fragmentation of the analogous carbenes from benzyloxy-(p-substituted-benzyloxy)carbenes was determined by comparing the yields of the two possible esters, ArCH2O(CO)CH2Ph and PhCH2O(CO)CH2Ar. It was found that an electron-withdrawing group in the para position favoured fragmentation to the benzylic radical containing that group. A Hammett plot of the data gave a best fit with σ- substituent constants (r = 0.994, ρ((PhH, 110°C) = 0.7)) suggesting that the fragmentation involves charge separation in the sense that increases electron density on the group that is becoming a benzylic radical and decreases electron density on the carbonyl group that is becoming the benzyloxycarbonyl radical.
Prostaglandin E2-bisphosphonate conjugates: Potential agents for treatment of osteoporosis
Gil, Laurent,Han, Yongxin,Opas, Evan E.,Rodan, Gideon A.,Ruel, Rejean,Seedor, J. Gregory,Tyler, Peter C.,Young, Robert N.
, p. 901 - 919 (2007/10/03)
Conjugates of bisphosphonates (potential bone resorption inhibitors) and prostaglandin E2 (a bone formation enhancer) were prepared and evaluated for their ability to bind to bone and to liberate, enzymatically, free PGE2. The conjugate 3, an amide at C-1 of PGE2 proved to be too stable in vivo while conjugate 6, a thioester, was too labile. Several PGE2, C-15 ester-linked conjugates (18, 23, 24 and 31) were prepared and conjugate 23 was found to bind effectively to bone in vitro and in vivo and to liberate PGE2 at an acceptable rate. A 4-week study in a rat model of osteoporosis showed that 23 was better tolerated and more effective as a bone growth stimulant than daily maximum tolerated doses of free PGE2. Copyright (C) 1999 Elsevier Science Ltd.
Notice on a Reaction of Alcohols with the Phase Transfer Catalytic Dichlorocarbene System (Applications of Phase Transfer Catalysis, Part 36)
Dehmlow, Eckehard V.,Neuhaus, Rainer
, p. 796 - 798 (2007/10/02)
Primary aliphatic alcohols and HCCl3/NaOH/catalyst yield stereoisomeric 1,2-dialkoxytetrachlorocyclopropanes 4 and 5, benzyl and phenethyl alcohol give orthoformates (1).Compounds 4 suffer rearrangement/hydrolysis at 120 grad C yielding 3-alkoxy-2,3-dichloroacrylates. - Key words: 1,2-Dialkoxytetrachlorocyclopropanes, ortho Esters
