Phosphoric Acid → (S)-benzyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(aziridin-1-yl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)cyclohex-3-enecarboxylate

HRID 1400993Notes

Reaction equation

HRID 1400993 reaction equation
[NH2:1][C@:2]12[CH2:43][CH2:42][C@@H:41]([C:44]([CH3:46])=[CH2:45])[C@@H:3]1[C@@H:4]1[C@@:17]([CH3:20])([CH2:18][CH2:19]2)[C@@:16]2([CH3:21])[C@@H:7]([C@:8]3([CH3:40])[C@@H:13]([CH2:14][CH2:15]2)[C:12]([CH3:23])([CH3:22])[C:11]([C:24]2[CH2:29][CH2:28][C@H:27]([C:30]([O:32][CH2:33][C:34]4[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=4)=[O:31])[CH2:26][CH:25]=2)=[CH:10][CH2:9]3)[CH2:6][CH2:5]1.Br[CH2:48][CH2:49]Cl.P(=O)(O)(O)O.[K]>C(#N)C>[N:1]1([C@:2]23[CH2:43][CH2:42][C@@H:41]([C:44]([CH3:46])=[CH2:45])[C@@H:3]2[C@@H:4]2[C@@:17]([CH3:20])([CH2:18][CH2:19]3)[C@@:16]3([CH3:21])[C@@H:7]([C@:8]4([CH3:40])[C@@H:13]([CH2:14][CH2:15]3)[C:12]([CH3:23])([CH3:22])[C:11]([C:24]3[CH2:29][CH2:28][C@H:27]([C:30]([O:32][CH2:33][C:34]5[CH:35]=[CH:36][CH:37]=[CH:38][CH:39]=5)=[O:31])[CH2:26][CH:25]=3)=[CH:10][CH2:9]4)[CH2:6][CH2:5]2)[CH2:49][CH2:48]1

Participants

6

Reactant 4

HCID 1004Phosphoric AcidHCID 78491-Bromo-2-ChloroethaneHCID 5462222PotassiumHCID 86692348(S)-benzyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)cyclohex-3-enecarboxylate

Product 1

HCID 86692350(S)-benzyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(aziridin-1-yl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)cyclohex-3-enecarboxylate

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
120 °C

Procedure

To a sealable vial was added (S)-benzyl 4-((1R,3 aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)cyclohex-3-enecarboxylate (0.042 g, 0.067 mmol), 1-bromo-2-chloroethane (0.056 ml, 0.673 mmol) and phosphoric acid, potassium salt (0.071 g, 0.337 mmol). The mixture was diluted with acetonitrile (1 mL), was flushed with nitrogen, then was sealed and heated to 120° C. After 23 h of heating, the mixture was cooled to rt and the reaction mixture was filtered to remove solids. The solids were washed with dichloromethane and the filtrate was concentrated under reduced pressure to give (S)-benzyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(aziridin-1-yl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)cyclohex-3-enecarboxylate as an off-white solid. The crude product was used in the next step with no additional purification. LCMS: m/e 650.8 (M+H)+, 2.26 min (method 1).

Workup

  1. customwas flushed with nitrogen
  2. customwas sealed
  3. temperatureAfter 23 h of heating
  4. temperaturethe mixture was cooled to rt
  5. filtrationthe reaction mixture was filtered
  6. customto remove solids
  7. washThe solids were washed with dichloromethane
  8. concentrationthe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-6c4f2a423e0f480c8724b0be5338e8b7
Source dataset
uspto-grants-2014_12
Patent number
US08906889B2

Reaction notes

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