Isopropanol → ethyl 1-benzyl-6-chloro-1H-pyrazolo[3,4-b]pyridine-4-carboxylate

HRID 574991Notes

Reaction equation

P(Cl)(Cl)([Cl:3])=O.[CH2:6]([N:13]1[C:17]2[N:18]=[C:19](O)[CH:20]=[C:21]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[C:16]=2[CH:15]=[N:14]1)[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.C(O)(C)C>CN(C=O)C>[CH2:6]([N:13]1[C:17]2[N:18]=[C:19]([Cl:3])[CH:20]=[C:21]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[C:16]=2[CH:15]=[N:14]1)[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1

Participants

Conditions

Temperature: 80 °C

Procedure

Phosphoryl trichloride (74 mL/0.81 mol) is added dropwise to a solution of ethyl 1-benzyl-6-hydroxy-1H-pyrazolo[3,4-b]pyridine-4-carboxylate [CAS 74439-45-5] (40.0 g/0.135 mol) in 450 mL of DMF at 0° C. under nitrogen. The reaction medium is stirred at 80° C. for 24 hours so as to give a dark brown solution. It is then run into a mixture of ice-cold water, and extracted with EtOAc. The organic phase is washed with water, dried with sodium sulphate, filtered and concentrated to dryness. The solid obtained is taken up with isopropanol, filtered, washed with diisopropyl ether and oven-dried to give 30.6 g of a yellow powder (yield: 72%).

Workup

customto give a dark brown solution
additionIt is then run into a mixture of ice-cold water
extractionextracted with EtOAc
washThe organic phase is washed with water
dry with materialdried with sodium sulphate
filtrationfiltered
concentrationconcentrated to dryness
customThe solid obtained
filtrationfiltered
washwashed with diisopropyl ether
customoven-dried

Sources & evidence

ORD record: ord-8dfd9bfd2e204ed9b3e6e53b9d9dd02f
Source dataset: uspto-grants-2015_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09034898B2

Reaction notes

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