Diisopropylethylamine → 3-Bromo-7-(1-methyl-1-triethylsilanyloxyethyl)imidazo[1,2-alpha]pyrimidine

HRID 1796034Notes

Reaction equation

HRID 1796034 reaction equation
FC(F)(F)S([O:6][Si:7]([CH2:12][CH3:13])([CH2:10][CH3:11])[CH2:8][CH3:9])(=O)=O.[Br:16][C:17]1[N:21]2[CH:22]=[CH:23][C:24]([C:26](O)([CH3:28])[CH3:27])=[N:25][C:20]2=[N:19][CH:18]=1.C(N(C(C)C)CC)(C)C>ClCCl>[Br:16][C:17]1[N:21]2[CH:22]=[CH:23][C:24]([C:26]([CH3:28])([O:6][Si:7]([CH2:12][CH3:13])([CH2:10][CH3:11])[CH2:8][CH3:9])[CH3:27])=[N:25][C:20]2=[N:19][CH:18]=1

Participants

5

Procedure

Triethylsilyl trifluoromethanesulfonate (4.85 ml, 21.5 mmol) was added dropwise over 15 min to a cooled (−50° C.) solution of 2-(3-bromoimidazo[1,2-α]pyrimidin-7-yl)propan-2-ol (5.0 g, 19.5 mmol) and diisopropylethylamine (4.76 ml, 27.5 mmol) in dichloromethane (150 ml). The mixture was stirred for 20 min then allowed to warm to ambient temperature overnight. The reaction mixture was diluted with dichloromethane (100 ml) and washed with 1N hydrochloric acid (100 ml) and water (100 ml), dried over anhydrous magnesium sulfate, filtered and evaporated. The red oil was purified by dry flash column chromatography on silica eluting with dichloromethane on a gradient of methanol (0-3%). Collecting the appropriate fractions gave 3-bromo-7-(1-methyl-1-triethylsilanyloxyethyl)imidazo[1,2-α]pyrimidine as a pale yellow oil which crystallised on standing (6.21 g, 86%): δH (400 MHz, CDCl3) 0.64 (6H, q, J 8), 0.97 (9H, t, J 8), 7.50 (1H, d, J 7), 7.72 (1H, s), 8.35 (1H, d, J 7).

Workup

  1. washwashed with 1N hydrochloric acid (100 ml) and water (100 ml)
  2. dry with materialdried over anhydrous magnesium sulfate
  3. filtrationfiltered
  4. customevaporated
  5. customThe red oil was purified
  6. dry with materialby dry flash column chromatography on silica eluting with dichloromethane on a gradient of methanol (0-3%)
  7. customCollecting the appropriate fractions

Sources & evidence

ORD record
ord-9500595a69d14aa489c407fa205b6bf5
Source dataset
uspto-grants-2006_04
Patent number
US07030128B2

Reaction notes

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