- Regioselective monochloro substitution in carbohydrates and non-sugar alcohols via Mitsunobu reaction: Applications in the synthesis of reboxetine
-
A regioselective high yielding monochloro substitution (chlorohydrin formation) via Mitsunobu reaction is reported. In carbohydrates and sterically hindered non-sugars, only the primary hydroxyl group is chlorinated, whereas in the non-sugar 1,2- and 1,3-alcohols, predominantly the secondary chloride substitution occurs. The versatile methodology provides indirect access to epoxides with the retention of configuration, as against conventional Mitsunobu reaction which generates epoxides with inversion. The methodology was successfully used as a key step in the synthesis of optically active diastereoisomers of the antidepressant drug reboxetine from (R)-2,3-O- cyclohexylidene-d-glyceraldehyde in ~43% overall yields. The Royal Society of Chemistry.
- Dar, Abdul Rouf,Aga, Mushtaq A.,Kumar, Brijesh,Yousuf, Syed Khalid,Taneja, Subhash Chandra
-
p. 6195 - 6207
(2013/09/12)
-
- The use of environmental metrics to evaluate green chemistry improvements to the synthesis of (S,S)-reboxetine succinate
-
The Pfizer Green Chemistry metrics program is described and exemplified with a case history involving the synthesis of (S,S)-reboxetine succinate. The initial route used a classical resolution approach and generated high levels of waste. This route was replaced by an enantiospecific synthesis which used Sharpless epoxidation chemistry, an enzymatic process to selectively protect a primary alcohol and a new efficient method of chiral morpholine construction as key steps. These improvements reduced the levels of waste produced by the synthesis by more than 90%. Detailed metrics starting from a common starting material (trans-cinnamyl alcohol) for all routes of synthesis are presented.
- Assaf, Georges,Checksfield, Graham,Critcher, Doug,Dunn, Peter J.,Field, Stuart,Harris, Laurence J.,Howard, Roger M.,Scotney, Gemma,Scott, Adam,Mathew, Suju,Walker, Geoffrey M. H.,Wilder, Alexander
-
scheme or table
p. 123 - 129
(2012/04/11)
-
- Process development and scale-up for (±)-reboxetine mesylate
-
Redevelopment of the commercial process for the synthesis of (±)-reboxetine methanesulfonate is described. An optimized and efficient process for the synthesis of (±)-reboxetine starting from cinnamyl alcohol was developed. The redeveloped process minimizes impurity formation and utilizes simplified processing to substantially improve process yield and throughput, and is suitable for the efficient synthesis of multiton quantities of reboxetine.
- Henegar, Kevin E.,Ball, Cynthia T.,Horvath, Carolyn M.,Maisto, Keith D.,Mancini, Sarah E.
-
p. 346 - 353
(2012/12/31)
-
- Method for the preparation of aryl ethers
-
The invention comprises an enantioselective method of preparing a compound of formula (IV): wherein n, m, R and R1 are as defined herein. Use of the compounds of formula (IV) in a method of preparing compounds of formula (IX) and novel intermediates useful in the method are also described.
- -
-
Page/Page column 10
(2008/06/13)
-