tert-Butyl acetate → (S)-methyl 2-(tert-butoxy)-2-(7-chloro-5-methyl-2-(5,6,7,8-tetrahydronaphthalen-2-yl)pyrazolo[1,5-a]pyrimidin-6-yl)acetate

HRID 574336Notes

Reaction equation

HRID 574336 reaction equation
[Cl:1][C:2]1[N:7]2[N:8]=[C:9]([C:11]3[CH:20]=[CH:19][C:18]4[CH2:17][CH2:16][CH2:15][CH2:14][C:13]=4[CH:12]=3)[CH:10]=[C:6]2[N:5]=[C:4]([CH3:21])[C:3]=1[C@H:22]([OH:27])[C:23]([O:25][CH3:26])=[O:24].C(O[C:32]([CH3:35])([CH3:34])[CH3:33])(=O)C.Cl(O)(=O)(=O)=O>C(Cl)Cl>[C:32]([O:27][C@@H:22]([C:3]1[C:4]([CH3:21])=[N:5][C:6]2[N:7]([N:8]=[C:9]([C:11]3[CH:20]=[CH:19][C:18]4[CH2:17][CH2:16][CH2:15][CH2:14][C:13]=4[CH:12]=3)[CH:10]=2)[C:2]=1[Cl:1])[C:23]([O:25][CH3:26])=[O:24])([CH3:35])([CH3:34])[CH3:33]

Participants

5

Reactant 3

HCID 10908tert-Butyl acetateHCID 24247Perchloric AcidHCID 86670288(S)-methyl 2-(7-chloro-5-methyl-2-(5,6,7,8-tetrahydronaphthalen-2-yl)pyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate

Product 1

HCID 86670289(S)-methyl 2-(tert-butoxy)-2-(7-chloro-5-methyl-2-(5,6,7,8-tetrahydronaphthalen-2-yl)pyrazolo[1,5-a]pyrimidin-6-yl)acetateYield 72.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of (S)-methyl 2-(7-chloro-5-methyl-2-(5,6,7,8-tetrahydronaphthalen-2-yl)pyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate (888 mg, 2.301 mmol) in CH2Cl2 (45 mL) and t-butyl acetate (21.76 mL, 161 mmol) at rt was added 70% perchloric acid (0.593 mL, 6.90 mmol). After 2.5 h, the reaction mixture was diluted with CH2Cl2 (50 mL), carefully quenched with sat. NaHCO3 (50 mL), organic layer separated and washed with brine (100 mL), dried (Na2SO4), filtered and concentrated to give yellow liquid. This was purified by flash column chromatography on silica gel column using (10-40% EtOAc/Hex as eluant) to afford the desired (S)-methyl 2-(tert-butoxy)-2-(7-chloro-5-methyl-2-(5,6,7,8-tetrahydronaphthalen-2-yl)pyrazolo[1,5-a]pyrimidin-6-yl)acetate (735 mg, 1.663 mmol, 72.3% yield) as white solid. 150 mg of starting material was also recovered. 1H NMR (500 MHz, CDCl3) δ 7.76-7.70 (m, 2H), 7.18 (d, J=7.9 Hz, 1H), 6.91 (s, 1H), 5.68 (s, 1H), 3.76 (s, 3H), 2.89-2.84 (m, 4H), 2.68 (s, 3H), 1.89-1.83 (m, 4H), 1.30 (s, 9H). LCMS (M+H)=444.3.

Workup

  1. customcarefully quenched with sat. NaHCO3 (50 mL), organic layer
  2. customseparated
  3. washwashed with brine (100 mL)
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give yellow liquid
  8. customThis was purified by flash column chromatography on silica gel column

Sources & evidence

ORD record
ord-d300b4516c6a4b2195019b59ec3a079d
Source dataset
uspto-grants-2015_05
Patent number
US09034882B2

Reaction notes

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