Piperonyl alcohol → 2(R)-[(3,4-methylenedioxybenzyl)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl)amino]-3-methylbutyric acid benzyl ester

HRID 2297969Notes

Reaction equation

HRID 2297969 reaction equation
[CH2:1]([O:8][C:9](=[O:29])[C@H:10]([NH:14][S:15]([C:18]1[C:23]([CH3:24])=[CH:22][C:21]([O:25][CH3:26])=[C:20]([CH3:27])[C:19]=1[CH3:28])(=[O:17])=[O:16])[CH:11]([CH3:13])[CH3:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:30]1[O:34][C:33]2[CH:35]=[C:36]([CH2:39]O)[CH:37]=[CH:38][C:32]=2[O:31]1.C(P(CCCC)CCCC)CCC.N(C(N1CCCCC1)=O)=NC(N1CCCCC1)=O>C1C=CC=CC=1>[CH2:1]([O:8][C:9](=[O:29])[C@H:10]([N:14]([CH2:39][C:36]1[CH:37]=[CH:38][C:32]2[O:31][CH2:30][O:34][C:33]=2[CH:35]=1)[S:15]([C:18]1[C:23]([CH3:24])=[CH:22][C:21]([O:25][CH3:26])=[C:20]([CH3:27])[C:19]=1[CH3:28])(=[O:17])=[O:16])[CH:11]([CH3:13])[CH3:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 10322Piperonyl alcoholHCID 13831TributylphosphineHCID 730421,1'-(Azodicarbonyl)dipiperidineHCID 114869322(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-methylbutyric acid benzyl ester

Product 1

HCID 111804222(R)-[(3,4-methylenedioxybenzyl)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl)amino]-3-methylbutyric acid benzyl esterYield 80.9%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To a mixture of 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-methylbutyric acid benzyl ester (4.5 g, 10.72 mmol), 3,4-(methylenedioxy)phenylmethanol (2.04 g, 13.41 mmol), and tributylphosphine (3.35 mL, 13.4 mmol) in dry benzene (60 mL) cooled in an ice bath was added 1,1′-(azodicarbonyl)dipiperidine (3.38 g, 13.4 mmol). The reaction mixture was stirred overnight to room temperature and then flash chromatographed on a silica gel column (5-10% ethyl acetate/hexanes) to give 2(R)-[(3,4-methylenedioxy-benzyl)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl)amino]-3-methylbutyric acid benzyl ester (4.8 g) as a white solid.

Workup

  1. temperaturecooled in an ice bath
  2. customflash chromatographed on a silica gel column (5-10% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-72ab789bf56d4443b30b4f8807f4abaf
Source dataset
uspto-grants-2002_12
Patent number
US06492394B1

Reaction notes

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