Editing Synthesis of DSP and DTBP (section)

== DSP&nbsp; ==

[[File:DSP structure.jpg|RTENOTITLE]]



A typical preparation of dithiobis-(succinimidyl propionate) can be accomplished as follows: to a solution of '''dithiodipropionic acid''' (105.15 gm, 0.5 M, MW: 210.27), http://www.sigmaaldrich.com/catalog/product/aldrich/109010?lang=en&region=US, 109010-250G $ 63.30

[[File:3 3 -Dithiobis Propanoic acid.png|RTENOTITLE]]

'''N-hydroxysuccinimide&nbsp;'''(115.09 g, 1.0 mole,&nbsp;Molecular Weight 115.09,&nbsp; 130672-100G, $91.30, 130672-250G, $247.50, [https://us.vwr.com/store/catalog/product.jsp?catalog_number=200001-338 https://us.vwr.com/store/catalog/product.jsp?catalog_number=200001-338], acros organics 250 g AC15727-2500 200001-338 $189.78)

[[File:N-hydroxysuccinimide.png|RTENOTITLE]]





in 600 ml of '''Tetrahydrofuran''' (360589-500ML, $74.20; 360589-1L, 97.90) at -5° C. was added dropwise a solution of 206.32 gm (1.0 m) of '''dicyclohexylcarbodiimide''' (D80002-100G, $55.00; D80002-500G, $191.00, NN'-DICYCLHXYLCARBODIIMID 500G

[[File:Dicyclohexylcarbodiimide.png|RTENOTITLE]]<br/>&nbsp;N,N'-Dicyclohexylcarbodiimide Catalog Number: AAA10973-36 Supplier: Alfa Aesar, $108.71) in 100 ml of THF. The resulting reaction mixture was stirred at 0° C. for 24 hrs. After an additional 24 hrs. stirring at room temperature, the solid by-product, dicyclohexylurea, was filtered off and discarded. The filtrate was evaporated to dryness, taken up in '''ethyl acetate'''&nbsp;(270989-1L, $72.70, 270989-2L, $104.00) and the desired product precipitated by addition of '''hexane''' (296090-1L, $88.20). The product after drying is a white (yield - 90 g) powder M.P. 63°-5°. Further purification by recrystallization yields a product having a melting point of about 121°-123° C.