Potassium Hydroxide → (2S,4R)-4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]pyrazol-1-yl]-1-tert-butoxycarbonyl-pyrrolidine-2-carboxylic acid

HRID 908435Notes

Reaction equation

HRID 908435 reaction equation
[OH-].[K+].[NH2:3][C:4]1[N:9]=[CH:8][C:7]([C:10]2[CH:11]=[N:12][N:13]([C@H:15]3[CH2:19][N:18]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[C@H:17]([C:27]([O:29]C)=[O:28])[CH2:16]3)[CH:14]=2)=[CH:6][C:5]=1[C:31]1[O:32][C:33]2[CH:39]=[CH:38][CH:37]=[CH:36][C:34]=2[N:35]=1>CO>[NH2:3][C:4]1[N:9]=[CH:8][C:7]([C:10]2[CH:11]=[N:12][N:13]([C@H:15]3[CH2:19][N:18]([C:20]([O:22][C:23]([CH3:25])([CH3:26])[CH3:24])=[O:21])[C@H:17]([C:27]([OH:29])=[O:28])[CH2:16]3)[CH:14]=2)=[CH:6][C:5]=1[C:31]1[O:32][C:33]2[CH:39]=[CH:38][CH:37]=[CH:36][C:34]=2[N:35]=1

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 67388265(2S,4R)-O1-tert-butyl O2-methyl 4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]pyrazol-1-yl]pyrrolidine-1,2-dicarboxylate

Product 1

HCID 67389021(2S,4R)-4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]pyrazol-1-yl]-1-tert-butoxycarbonyl-pyrrolidine-2-carboxylic acidYield 47.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
50 °C

Procedure

(2S,4R)—O1-tert-butyl O2-methyl 4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]pyrazol-1-yl]pyrrolidine-1,2-dicarboxylate was prepared according to the procedure described in Example 26 except that caesium carbonate was used, using (2S,4S)—O1-tert-butyl O2-methyl 4-methylsulphonyloxypyrrolidine-1,2-dicarboxylate (Siddiqui et al., PCT. Int. Appl. US2007/0167426) as alkylating agent to give 442 mg of solid. NMR Spectrum: (CDCl3) 1.45 (s, 5.4H), 1.48 (s, 3.6H), 2.44-2.52 (m, 1H). 2.82-2.96 (m, 1H), 3.79 (s, 1.8H), 3.80 (s, 1.2H), 3.82-3.89 (m, 0.4H), 3.92-3.98 (m, 0.6H), 4.03-4.11 (m, 1H), 4.49-4.55 (m, 0.6H), 4.60-4.65 (m, 0.4H), 4.99-5.10 (m, 1H), 7.05 (bs, 2H), 7.35-7.42 (m, 2H), 7.59-7.63 (m, 1H), 7.68 (s, 1H), 7.74-7.78 (m, 1H), 7.81 (d, 1H), 8.35 (d, 1H), 8.40 (d, 1H) Mass spectrum: M+H+ 505 A solution of potassium hydroxide (1.249 ml, 2N) was added to (2S,4R)—O1-tert-butyl O2-methyl 4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]pyrazol-1-yl]pyrrolidine-1,2-dicarboxylate (420 mg) dissolved in methanol (10 ml) over a period of 10 minutes under argon. The resulting solution was stirred at 50° C. for 2 hours. The methanol was evaporated and the pH was adjusted to 5.5 with HCl 6N. The mixture was evaporated on reduce pressure. The reaction mixture was purified by preparative HPLC using a Waters X-Terra reverse-phase column (C-18, 5 microns silica, 19 mm diameter, 100 mm length, flow rate of 40 ml/minute) and decreasingly polar mixtures of water (containing 0.2% ammonium carbonate) and acetonitrile as eluent. The fractions containing the desired compound were evaporated to dryness to afford (2S,4R)-4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]pyrazol-1-yl]-1-tert-butoxycarbonyl-pyrrolidine-2-carboxylic acid (195 mg) as a solid. NMR Spectrum: (DMSOd6) 1.35 (s, 5.4H), 1.39 (s, 3.6H), 2.32-2.43 (m, 1H), 2.66-2.82 (m, 1H), 3.63-3.71 (m, 1H), 3.80-3.89 (m, 1H), 4.28-4.36 (m, 1H), 4.96-5.06 (m, 1H), 7.40-7.49 (m, 2H), 7.67 (bs, 2H), 7.77-7.81 (m, 1H), 7.82-7.86 (m, 1H), 7.97 (s, 1H), 8.36 (s, 0.6H), 8.39 (s, 0.4H), 8.41-8.46 (m, 1H), 8.50-8.55 (m, 1H); Mass spectrum: M+H+ 491

Workup

  1. customThe methanol was evaporated
  2. customThe mixture was evaporated
  3. customThe reaction mixture was purified by preparative HPLC
  4. additionThe fractions containing the desired compound
  5. customwere evaporated to dryness

Sources & evidence

ORD record
ord-0ef49da54a244b8eb1515d841e9afe92
Source dataset
uspto-grants-2011_09
Patent number
US08017611B2

Reaction notes

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