Sodium Hydroxide → HCID 10222027, compound

HRID 1743643Notes

Reaction equation

HRID 1743643 reaction equation
C[O:2][C:3](=[O:23])[C@H:4]([CH2:13][S:14][C:15]1[CH:20]=[CH:19][C:18]([Br:21])=[CH:17][C:16]=1[NH2:22])[NH:5][C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7].[OH-].[Na+]>CC(OC)(C)C>[C:9]([O:8][C:6]([NH:5][C@H:4]([C:3]([OH:23])=[O:2])[CH2:13][S:14][C:15]1[CH:20]=[CH:19][C:18]([Br:21])=[CH:17][C:16]=1[NH2:22])=[O:7])([CH3:12])([CH3:10])[CH3:11]

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 58604709HCID 58604709, compound

Product 1

HCID 10222027HCID 10222027, compoundYield 100%

Reagents, catalysts & solvents 1

HCID 15413tert-Butyl methyl etherSolvent

Procedure

19.9 g (48.02 mmol) of N-tert-butoxycarbonyl-3-(2-amino-4-bromophenylthio)-L-alanine methyl ester (97.8%) was dissolved in 750 ml TBME and emulsified in 3 L buffer solution (0.1M sodium chloride, 20 mM sodium phosphate pH 7.5) under vigorous stirring. 12.0 ml Alcalase 2.4 L and 30 mg Substilisin A [both enzyme preparations are subtilisin Carlsberg from Novo Nordisk] were added and the pH was maintained at 7.5 under vigorous stirring by the controlled addition (pH-static) of 1.0N sodium hydroxide solution. After 7d 44.75 ml of 1.0N sodium hydroxide solution was consumed and the conversion degree was >99% (HPLC analysis). The biphasic reaction mixture was separated. The aqueous phase was washed briefly with 1 L TBME for the separation of small amounts of lipophilic impurities and traces of the remaining substrate. The combined organic phases were extracted with 1×250 ml 0.1 M potassium phosphate buffer pH 7.6. The combined aqueous phases were acidified to pH 2 with 32% hydrochloric acid and extracted with 1.5 L ethyl acetate. The resulting emulsion was separated by the addition of 10% Dicalite under stirring and a subsequent filtration. The aqueous phase was extracted with 2×1 L ethyl acetate. The combined ethyl acetate phases were dried on anhydrous sodium sulfate and evaporated. The residue was dissolved in dichloromethane, evaporated and dried at HV to give 18.79 g N-tert-butoxycarbonyl-3-(2-amino-4-bromophenylthio)-L-alanine as a pale yellow solid (yield: 81.8%). Analytical data: 1H-NMR (CDCl3, 400 MHz) 1.399 (s, 9H, OC(CH3)); 3.184 (dd, 1H, SCH2, J=14.2 Hz, J=6.6 Hz); 3.235 (dd, 1H, SCH2, J=14.2 Hz, J=6.6 Hz); 4.515 (m, 1H, COCHNH); 5.517 (d, 1H, CONHCH, J=6.8 Hz); 6.796 (dd, 1H, arom., J=2 Hz, J=8.4 Hz); 6.876 (d, 1H, arom., J=2 Hz); 7.250 (d, 1H, arom., J=8.4 Hz). IR (ATR-IR) 3445 and 3355 cm−1 (—NH, —NH2); 2978 and 2929 cm−1 broad (—COOH); 1693 cm−1 (COOH —C═O, carbamate —C═O); 1508 cm−1 (amide —CO—NH); 1247 and 1157 cm−1 (COOH). MS (ESI-positive ionization) m/z=391.1 [M+H+] with 79Br; m/z=393.1 [M+H+] with 81Br; m/z=413.2 [M+Na+] with 79Br; m/z=415.2 [M+Na+] with 81Br. OR [α]D=+53.3° (CHCl3; c=1.0). HPLC analysis: column: ABZ+plus; mobile phase: A: 0.1% TFA in H20; B: MeCN; gradient B: 30–80% 0–15 min, 80–30% 15–16 min, 30% 16–19.5 min; flow:1 ml/min; pressure: 50–80 bar; detection: UV, 300 nm; retention times: 12.1 min (product-acid) 13.5 min (substrate-ester).

Workup

  1. additionwere added
  2. temperaturethe pH was maintained at 7.5
  3. customAfter 7d 44.75 ml of 1.0N sodium hydroxide solution was consumed
  4. customThe biphasic reaction mixture
  5. customwas separated
  6. washThe aqueous phase was washed briefly with 1 L TBME for the separation of small amounts of lipophilic impurities and traces of the remaining substrate
  7. extractionThe combined organic phases were extracted with 1×250 ml 0.1 M potassium phosphate buffer pH 7.6
  8. extractionextracted with 1.5 L ethyl acetate
  9. customThe resulting emulsion was separated by the addition of 10% Dicalite
  10. filtrationa subsequent filtration
  11. extractionThe aqueous phase was extracted with 2×1 L ethyl acetate
  12. dry with materialThe combined ethyl acetate phases were dried on anhydrous sodium sulfate
  13. customevaporated
  14. dissolutionThe residue was dissolved in dichloromethane
  15. customevaporated
  16. customdried at HV

Sources & evidence

ORD record
ord-468ee538f3154783b23f2b9a59dec8d8
Source dataset
uspto-grants-2006_03
Patent number
US07011960B2

Reaction notes

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