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2nd December 2010 @ 05:35
Scale-up of [url=http://www.ourexperiment.org/racres_pzq/687]Synthesis of (-)-Dibenzoyl-L-tartaric acid (MW10-1-30)[/url] See also: See [url=http://www.ourexperiment.org/racres_pzq/921]Synthesis of (+)-Dibenzoyl-D-tartaric acid (MW10-5)[/url] and [url=http://www.ourexperiment.org/racres_pzq/934]Synthesis of (+)-Dibenzoyl-D-tartaric acid - alternative route (MW10-6)[/url] [data=size:500x160]487[/data] [b]Hazard and Risk Assessment:[/b] [data]575[/data] Start time: 4:00 PM 02/12/2010 End time: 8:00 PM 02/12/2010 [b]Procedure:[/b] [1] A mixture L-(+)-tartaric acid (27.0 g, 180 mmol, M.W. 150.1 g/mol) and benzoyl chloride (88.6 g, 73 mL, 630 mmol; M.W. 140.6 g/mol, 1.21 g/mL) was heated to 130°C for 4 h. After which time a pale yellow solid was formed. The mixture was cooled to room temperature, washed with cold Et2O and recrystallized from toluene (400 mL). [u]Yield of the anhydride:[/u] 48.3 g (141 mmol, 79%) colorless, crysalline solid [Anhydride, C18H12O7 M.W. = 340.3 g/mol] [Dibenzoyl-tartaric acid, M.W. = 358.3 g/mol] [Dibenzoyl-tartaric acid * 2 i-PrOH, C24H30O10 M.W. = 478.5 g/mol] [b]Hydrolysis of the anhydride:[/b] Start time: 3:00 PM 03/12/2010 End time: 5:00 PM 03/12/2010 The anhydride (48.3 g, 141 mmol) was dissolved in a mixture of acetone (200 mL) and water (20 mL) and heated to reflux for 2 h. Water (200 mL) was added and aceton was removed under reduced pressure. After further addition of water (200 mL) the mixture was heated refluxed and cooled to 0°C for 30 min. The water was removed by filtration and the colorless solid residue was freeze-dried (alternative method: dissolving solid in ethyl acetate and dry over Na2SO4). The solid was recrystallized from i-PrOH/hexane: 1. crystallization ~ 50 g from i-PrOH/hexane (~ 500 mL 1:1): yield 28.3 g (59.0 mmol, 33%) 2. crystallization 33 g from i-PrOH/hexane (~ 400 mL 1:2): yield 24.4 g (51.0 mmol, 28%), remain 8.5 g 3. crystallization (8.5 g) from i-PrOH/hexane (~ 50 mL 1:2): yield 6.22 g (13.0 mmol, 7%) -> Yield 58.9 g (123 mmol, 68%) (-)-dibenzoyl-L-tartaric acid * 2 i-PrOH [M.W.(C24H30O10) = 478.5 g/mol] [b]Analytical data:[/b] m.p. 98-100°C (lit. 95–98°C for DBTA * H2O [3]) 1H NMR (DMSO-d6, 200 MHz): δ = 1.03 (d, J=6 Hz, 12H), 3.78 (sep, J=6 Hz, 2H), 5.88 (s, 2H), 7.57-7.64 (m, 4H), 7.70-7.74 (m, 2H), 8.00-8.04 (m, 4H), 14.00 (bs, 2H). [data=text]685[/data] 13C NMR (DMSO-d6, 50.3 MHz): δ = 25.5 (4C), 62.2 (2C), 71.6 (2C), 128.6 (2C), 129.1 (4C), 129.5 (4C), 134.2 (2C), 164.8 (2C), 167.3 (2C). [data=text]669[/data] IR (neat): nu = 3465 cm-1, 2975, 1730, 1237, 1098, 938, 706.Data: MW10-1-30 acid.pdf -> no OH-peak for i-PrOH [data=text]589[/data] [α]D20 = -85.0° (c=1, EtOH). ([α]D20 = 119.4° (c=1.055, MeOH)) MS (ESI (-)) m/z (%): 357 (100) [M-H]-. HRMS (ESI (-)) Calcd. for [ C18H13O8]-: 357.0616, found: 357.0616. HRMS (ESI (+)) Calcd. for [C18H14O8+Na]+: 381.0581, found: 381.0579. C24H30O10 (478.5 g/mol): calc. C 60.24%, H 6.32%; found: C 60.27%, H 6.33% -> dibenzoyltartaric acid * 2 i-PrOH More spectra and data: [*] [url=http://www.ourexperiment.org/racres_pzq/934]Synthesis of (+)-Dibenzoyl-D-tartaric acid - alternative route (MW10-6)[/url] [*] [url=http://www.ourexperiment.org/racres_pzq/921]Synthesis of (+)-Dibenzoyl-D-tartaric acid (MW10-5)[/url] [*] [url=http://www.ourexperiment.org/racres_pzq/687]Synthesis of (-)-Dibenzoyl-L-tartaric acid (MW10-1-30)[/url] [b]Results:[/b] The procedure for the synthesis of (-)-dibenzoyl-L-tartaric acid is easy to scale-up also the purification / separation from the side product benzoic acid is not a problem. However the product couldn't be crystallized from water as (-)-dibenzoyl-L-tartaric acid monohydrate (neccessary?) therefore it was recrystallized from iso-propanol/hexane. Yield could be improved but ordering the chemical from a chemical supplier is more economic... (AU$ 16 per kg (-)-dibenzoyl-L-tartaric acid monohydrate for an order volume of 1000 kg) [b]References:[/b] [url=http://dx.doi.org/10.1021/ja01154a083][1] “The Reduction of Various Sugar Acids to Glycitols with Lithium Aluminum Hydride”, R. K. Ness, H. G. Fletcher and C. S. Hudson,[i] J. Am. Chem Soc.[/i] [b]1951[/b], [i]73[/i], 10, 4759-4761.[/url] [url=http://www.publish.csiro.au/nid/51/paper/CH9870399.htm][2] “Relative Stereoselectivity of the Reactions of (2R,3R)- and (2R,3S)-Dibenzoyloxysuccinic Anhydrides with Chiral Amines and Alcohols”, K. H. Bell, Aust. J. Chem. 1987, 40, 399-404. doi:10.1071/CH9870399.[/url] [url=http://onlinelibrary.wiley.com/doi/10.1002/adsc.200404296/abstract][3] "Convenient and Inexpensive Synthesis of (1R,2R)- trans-1-Amino-6-nitroindan-2-ol", S. Kozhushkov, D. Yufit and A. de Meijere, Adv. Synth. Catal. 2005, 347, 255– 265.[/url] (for analytical data references) [url=http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_EP&FT=D&date=20021017&CC=US&NR=2002151717A1&KC=A1][4] "Novel processes for the preparation or (R)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol", Daugs et al. US Patent Application (2002), US 2002/0151717A1. [/url] [Example 53, p. 42]
Attached Files
1H NMR MW10-7.pdf
1H NMR MW10-7 JCAMP-DX.dx