Dimethyl Sulfoxide → Ethyl 2-(tert-butoxycarbonylamino)-2-formyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate

HRID 579516

Reaction equation

HRID 579516 reaction equation
C(Cl)(=O)C(Cl)=O.CS(C)=O.[C:11]([O:15][C:16]([NH:18][C:19]([CH2:38][OH:39])([CH2:25][CH2:26][CH2:27][CH2:28][B:29]1[O:33][C:32]([CH3:35])([CH3:34])[C:31]([CH3:37])([CH3:36])[O:30]1)[C:20]([O:22][CH2:23][CH3:24])=[O:21])=[O:17])([CH3:14])([CH3:13])[CH3:12].C(N(CC)CC)C>ClCCl>[C:11]([O:15][C:16]([NH:18][C:19]([CH:38]=[O:39])([CH2:25][CH2:26][CH2:27][CH2:28][B:29]1[O:30][C:31]([CH3:37])([CH3:36])[C:32]([CH3:35])([CH3:34])[O:33]1)[C:20]([O:22][CH2:23][CH3:24])=[O:21])=[O:17])([CH3:14])([CH3:12])[CH3:13]

Participants

6

Reactant 4

HCID 679Dimethyl SulfoxideHCID 8471TriethylamineHCID 65578Oxalyl chlorideHCID 66833197Ethyl 2-(tert-butoxycarbonylamino)-2-(hydroxymethyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate

Product 1

HCID 86663719Ethyl 2-(tert-butoxycarbonylamino)-2-formyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoateYield 57%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

While under an argon atmosphere, a solution of oxalyl chloride (1.46 g, 0.88 mL, 11.6 mmol) in dichloromethane (15 mL) was cooled to −78° C. and treated with dimethyl sulfoxide (1.8 g, 1.64 mL, 23.2 mmol) and stirred for 10 minutes. To this mixture ethyl 2-(tert-butoxycarbonylamino)-2-(hydroxymethyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (2.4 g, 5.78 mmol) in anhydrous dichloromethane (15 mL) was added and the mixture was stirred for 30 minutes. The reaction mixture was quenched by adding triethylamine (3.5 g, 4.8 mL, 34.7 mmol) at −78° C. and slowly warming the reaction mixture to room temperature. The mixture was diluted with dichloromethane (25 mL) and washed successively with water (2×25 mL) and saturated aqueous sodium chloride (25 mL). Organic layer was dried over magnesium sulfate, filtered and evaporated to dryness. The resulting residue was purified using a combiflash system (40 g column, eluted with 20-40% ethyl acetate in heptanes) to give ethyl 2-(tert-butoxycarbonylamino)-2-formyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (1.35 g, 57%). 1HNMR (CDCl3) δ 9.58 (s, 1H), 5.64 (bs, 1H), 4.25 (m, 2H), 2.13 (m, 2H), 1.45 (m, 9H), 1.28 (m, 4H), 1.24 (s, 12H), 0.88 (t, J=6.4 Hz, 3H), 0.77 (t, J=7.9 Hz, 2H). MS found for C20H36BNO7 m/z[436(M+Na)].

Workup

  1. stirringthe mixture was stirred for 30 minutes
  2. customThe reaction mixture was quenched
  3. washwashed successively with water (2×25 mL) and saturated aqueous sodium chloride (25 mL)
  4. dry with materialOrganic layer was dried over magnesium sulfate
  5. filtrationfiltered
  6. customevaporated to dryness
  7. customThe resulting residue was purified
  8. washa combiflash system (40 g column, eluted with 20-40% ethyl acetate in heptanes)

Sources & evidence

ORD record
ord-252601c45157424bb74481dfac5052a4
Source dataset
uspto-grants-2015_05
Patent number
US09040703B2

Linked notes

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