DR ANTHONY MELVIN CRASTO,WorldDrugTracker, helping millions, A 90 % paralysed man in action for you, I am suffering from transverse mylitis and bound to a wheel chair, With death on the horizon, nothing will not stop me except God................DR ANTHONY MELVIN CRASTO Ph.D ( ICT, Mumbai) , INDIA 25Yrs Exp. in the feld of Organic Chemistry,Working for GLENMARK GENERICS at Navi Mumbai, INDIA. Serving chemists around the world. Helping them with websites on Chemistry.Million hits on google, world acclamation from industry, academia, drug authorities for websites, blogs and educational contribution

Thursday 18 September 2014

(1S,2S,5R,6S) -2-tert-Butoxycarbonylamino-bicyclo [3.1.0] hexane-2,6-dicarboxylic acid

Synthesis of (1S,2S,5R,6S) -2-tert-Butoxycarbonylamino-bicyclo [3.1.0] hexane-2,6-dicarboxylic acid

Figure US20040138304A1-20040715-C00013



 A 1 L flask was charged with (1S,2S,5R,6S)-2-amino-bicyclo [3.1.0]hexane-2,6-dicarboxylic acid monohydrate (24.4 g, 0.12 mol, 1 equiv), dioxane (200 mL) and di-tert-butyl dicarbonate (52.4 g, 0.24 mol, 2.0 equiv). The suspension was vigorously stirred while sodium hydroxide 1N (420 mL, 3.5 equiv) was added. The mixture was stirred for 2 days, then 2.0 more equiv of di-tert-butyl dicarbonate were added and the reaction stirred for 3 additional days at rt. After 5 total days of reaction, water (400 mL) was added to dissolve the salts. The aqueous layer was extracted with ethyl acetate (4×100 mL) to remove the excess of reagent, and then taken to ca. pH=2 using 6 N hydrochloric acid. The acidic aqueous phase was then extracted using ethyl ether (6×200 mL). The combined organic layers were washed with water (250 mL) and brine (250 mL). After drying over sodium sulfate, solvents were evaporated in vacuum to afford a foamy white solid (26.4 g).

77% Yield. 
mp 100-101° C. 

[α]D 25=−41.1° (c=1.0, MeOH). 

1H NMR (Methanol-d4) δ: 4.98 (brs, 1H), 2.44 (dd, 1H, J=6.2, 2.6 Hz), 2.19-1.92 (m, 4H), 1.62 (t, 1H, J=2.8 Hz), 1.43 (s, 9H), 1.29 (m, 1H). 


13C NMR (Methanol-d4) δ: 175.6, 175.2, 158.2, 60.1, 34.6, 31.9, 28.4, 27.2, 25.6, 20.6. MS (Neg. Electrospray): 284.2 (M+−H).

No comments:

Post a Comment