CarbaMic acid, N-[(1R)-1-(3-chlorophenyl)-2-hydroxyethyl]-, 1,1-diMethylethyl ester synthesis
- Product Name:CarbaMic acid, N-[(1R)-1-(3-chlorophenyl)-2-hydroxyethyl]-, 1,1-diMethylethyl ester
- CAS Number:926291-64-7
- Molecular formula:C13H18ClNO3
- Molecular Weight:271.74
4248-19-5
2039-85-2
926291-64-7
To a stirred solution of tert-butyl carbamate (2.0 eq.) in n-propanol (4 L/mol) in a cold water bath (~15°C) were sequentially added 1N NaOH (2.05 eq.) and tert-butyl hypochlorite (2.3 eq.). The reaction mixture was stirred for 10 minutes and then cooled to 0°C. Subsequently, a n-propanol (4 L/mol) solution of (DHQD)2PHAL (0.02 eq.), a n-propanol (8 L/mol) solution of m-chlorostyrene (1 eq.), and K2OsO4-2H2O (0.015 eq.) were added sequentially. Stirring was continued by keeping 0°C until the reaction was completed. Upon completion of the reaction, the reaction was quenched by addition of aqueous Na2SO3 solution until the reaction solution changed from green to yellow/brown. Concentrate the reaction mixture under reduced pressure. Standard post-treatment was performed: the reaction mixture was partitioned between water and CH2Cl2 to separate the phases and the aqueous phase was extracted with CH2Cl2. The organic phases were combined, dried with Na2SO4 or MgSO4, filtered and concentrated under reduced pressure. The crude product was purified by fast column chromatography on silica gel. 3-Chlorostyrene (28.0 g, 200 mmol) was converted to (R)-N-Boc-m-bromophenylglycinol (27.9 g, 51% yield, 99% HPLC purity, enantiomeric excess of 93.7% ee as determined by HPLC) according to General Method J. The product was purified by 1H NMR (1H NMR). The product was confirmed by 1H NMR (CD3OD): δ 3.63-3.72 (m, 2H), 4.63-4.67 (m, 1H), 7.26-7.37 (m, 2H), 7.43 (s, 1H).
4248-19-5
355 suppliers
$5.00/5g
2039-85-2
167 suppliers
$11.00/1g
926291-64-7
25 suppliers
$19.00/100mg
Yield:926291-64-7 51%
Reaction Conditions:
Stage #1: tert-butyl carbazatewith sodium hydroxide;tert-butyl hypochloride in propan-1-ol at 15; for 0.166667 h;
Stage #2: 3-Chlorostyrenewith (DHQD)2PHAL;potassium osmate(VI) in propan-1-ol at 0;
Steps:
J
To a stirred solution of t-butyl carbamate (2.0 equivalents) in n-propanol (4 L/mol) in a cold-water bath (~ 15°C) was added IN NaOH (2.05 equivalents), and t-butyl hypochlorite (2.3 equivalents). The mixture was stirred for 10 min and then cooled to 00C. Solutions of (DHQD)2PHAL (0.02 equivalents) in n-propanol (4 L/mol), styrene (1 equivalent) in n- propanol (8 L/mol), and K2OsO4-2H2O (0.015 equivalents) were added sequentially. The mixture was stirred at 00C until the reaction was complete. The reaction was quenched by the addition of an aqueous Na2SO3 solution until any remaining green color was reduced to yellow/brown. The mixture was concentrated under reduced pressure. In a standard workup, the reaction mixture was partitioned between water and CH2Cl2. The phases were separated and the aqueous extracted with CH2Cl2. The combined organic extracts were dried (Na2SO4 or MgSO4), filtered and concentrated under reduced pressure. The crude material was purified by flash column chromatography on silica gel.; Using general procedure J, 3-chlorostyrene (28.0 g, 200 mmol) was converted to [(R)-l-(3-chloro-phenyl)-2-hydroxy-ethyl]-carbamic acid tert-butyl ester (27.9g, 51% yield, 99% purity by HPLC, 93.7%ee by HPLC). 1H NMR (CD3OD) δ 3.63-3.72 (m, 2H), 4.63-4.67 (m, IH), 7.26-7.37 (m, 2H), 7.43 (s, IH).
References:
WO2007/22371,2007,A2 Location in patent:Page/Page column 27; 31