Trifluoroacetic acid → 3-[(Fluoren-9-ylmethyl)oxycarbonyl]pyrrolo[3,2-e]indoline-7-carboxylic acid

HRID 130599Notes

Reaction equation

HRID 130599 reaction equation
C([O:5][C:6]([N:8]1[C:19]2[C:11](=[C:12]3[C:16](=[CH:17][CH:18]=2)[NH:15][CH:14]([C:20]([OH:22])=[O:21])[CH2:13]3)[CH:10]=[CH:9]1)=[O:7])(C)(C)C.C(O)(C(F)(F)F)=O.ClC(O[CH2:34][CH:35]1[C:47]2[CH:46]=[CH:45][CH:44]=[CH:43][C:42]=2[C:41]2[C:36]1=[CH:37][CH:38]=[CH:39][CH:40]=2)=O>O>[CH:37]1[C:36]2[CH:35]([CH2:34][O:5][C:6]([N:8]3[C:19]4[C:11](=[C:12]5[C:16](=[CH:17][CH:18]=4)[NH:15][CH:14]([C:20]([OH:22])=[O:21])[CH2:13]5)[CH:10]=[CH:9]3)=[O:7])[C:47]3[C:42](=[CH:43][CH:44]=[CH:45][CH:46]=3)[C:41]=2[CH:40]=[CH:39][CH:38]=1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 343679-Fluorenylmethyl chloroformateHCID 667170523-(tert-Butyloxycarbonyl)pyrrolo[3,2-e]indoline-7-carboxylic acid

Product 1

HCID 686355913-[(Fluoren-9-ylmethyl)oxycarbonyl]pyrrolo[3,2-e]indoline-7-carboxylic acidYield 84.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

3-(tert-Butyloxycarbonyl)pyrrolo[3,2-e]indoline-7-carboxylic acid 8 (Boger et. al, J. Org. Chem. 52:1521 (1987)) (0.76 g, 2.4 mmol) was deprotected by a treatment with 5 mL of TFA for 1 h. TFA vas evaporated and the resultant trifluoroacetate dissolved in a mixture of 11% Na2CO3 (10 mL) and 5 mL of THF. 9-Fluorenylmethyl chloroformate (0.75 g, 2.9 mmol) was added and the reaction mixture was stirred for 3 h. The reaction was diluted with water (200 mL) and extracted with ethyl ether (2×50 mL). The aqueous phase was acidified by adding 1N HCl to pH 1-2. Precipitated product was collected by centrifugation, washed with water and dried under vacuum to afford 0.86 g (83%) of 9 as a yellow-gray solid.

Workup

  1. customTFA vas evaporated
  2. dissolutionthe resultant trifluoroacetate dissolved in a mixture of 11% Na2CO3 (10 mL) and 5 mL of THF
  3. extractionextracted with ethyl ether (2×50 mL)
  4. additionby adding 1N HCl to pH 1-2
  5. customPrecipitated product was collected by centrifugation
  6. washwashed with water
  7. customdried under vacuum

Sources & evidence

ORD record
ord-d9a053e09ad543f2a37d089f10a0aa63
Source dataset
uspto-grants-2008_06
Patent number
US07381818B2

Reaction notes

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