Diethylamine → 2,3-Dihydro-1,3-dimethyl-2-phenyl-1H-isophosphindole

HRID 2375951Notes

Reaction equation

HRID 2375951 reaction equation
C(NCC)C.[Li]CCCC.[C:11]1([PH2:17])[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.C1(P(C2C=CC=CC=2)(O[CH:27]([C:29]2[CH:34]=[CH:33][CH:32]=[CH:31][C:30]=2[CH:35](OP(C2C=CC=CC=2)(C2C=CC=CC=2)=O)[CH3:36])[CH3:28])=O)C=CC=CC=1.[OH-].[Na+]>C1COCC1.CC(OC)(C)C.O>[CH3:36][CH:35]1[C:30]2[C:29](=[CH:34][CH:33]=[CH:32][CH:31]=2)[CH:27]([CH3:28])[P:17]1[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

9

Reactant 5

HCID 8021DiethylamineHCID 12519PhenylphosphineHCID 14798Sodium HydroxideHCID 86603002HCID 86603002, compoundHCID 178418339Butyllithium

Product 1

HCID 693086282,3-Dihydro-1,3-dimethyl-2-phenyl-1H-isophosphindole

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×HCID 15413tert-Butyl methyl etherSolvent

Procedure

Under an atmosphere of nitrogen a Schlenk flask was charged with diethylamine (0.584 g, 8 mmol), to which a solution of n-BuLi (2.5 ml 1.6 N-solution in hexanes, 4 mmol) was added drop wise under efficient stirring. To the slightly hazy solution was then added phenyl phosphine (0.110 g, 1 mmol) which led to the formation of a yellow solution. This mixture was diluted with THF (2 ml), and immediately afterwards was added under efficient stirring a solution of diphenyl-phosphinic acid 1-{2-[1-(diphenyl-phosphinoyloxy)-ethyl]-phenyl}-ethyl ester (0.567 g, 1 mmol) in THF (made up to 2 ml total volume) drop wise over two minutes into the Schlenk flask. When the addition was complete, the mixture was stirred for another ten minutes. To the mixture was then added water (3 ml), sodium hydroxide (1 ml 40% solution in water), and TBME (15 ml). The mixture was stirred for 10 minutes, by which time two clear layers had formed. The aqueous layer was removed via syringe, and the organic layer was dried (Na2SO4). Removal of the solvent in vacuum left the product as colourless oil. 1H/13C-NMR (CDCl3, 300 MHz, HSQC/HMBC, indices A/B relate to syn/anti to P-lone pair) δ/δ 1.21 (dd, J=7.3 Hz, J=11.2 Hz)/14.45 (s) (B-CH3); 1.62 (dd, J=7.7 Hz, J=18.6 Hz)/21.73 (d, J=29.9 Hz) (A-CH3); 3.59 (dq, J=16.6 Hz)/40.04 (d, J=8.5 Hz) (A CHMe); 3.77 (dq, J=2.3 Hz)/35.57 (d, J=13.5 Hz) (B CHMe); 7.17 (m)/125.27 (d, J=1.1 Hz) (A Ar ortho-CH); 7.26 (m)/126.88, 7.26/127.22 (2 Ar meta-CH); 7.36 (m)/125.60 (d, J=1.3 Hz) (B Ar ortho-CH); 7.21 (m)/128.15 (d, J=7.2 Hz) (Ph meta-CH); 7.27 (m)/129.26 (d, J=1.0 Hz) (Ph para-Ch); 7.27 (m)/133.81 (d, J=19.8 Hz) (Ph ortho-CH); 135.90 (d, J=22.1 Hz) (Ph ipso-C); 145.09 (d, J=3.8 Hz) (B Ar ipso-C); 149.04 (d, J=2.3 Hz) (A Ar ipso-C). 31P-NMR δ 22.14.

Workup

  1. additionwas added drop wise under efficient stirring
  2. additionimmediately afterwards was added
  3. customwise over two minutes
  4. additionWhen the addition
  5. stirringThe mixture was stirred for 10 minutes, by which time two clear layers
  6. customhad formed
  7. customThe aqueous layer was removed via syringe
  8. dry with materialthe organic layer was dried (Na2SO4)
  9. customRemoval of the solvent in vacuum
  10. waitleft the product as colourless oil

Sources & evidence

ORD record
ord-003e20c4ae32489782d259fd8eb823a0
Source dataset
uspto-grants-2008_12
Patent number
US07465838B2

Reaction notes

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