2-Hydrazinoethanol → 2-[(2E)-2-[(3,5-dibromo-4-pyridinyl)methylidene]hydrazinyl]ethanol

Temperature

120 °C

In analogy to GP1, 468 mg of 3,5-dibromo-pyridine-4-carbaldehyde (1.77 mmol, 1 eq; commercially available or prepared as described in U.S. Pat. No. 6,232,320 or WO2005110410) were dissolved in 8 mL 1-propyl alkohol, treated with 0.36 mL 2-hydrazino-ethanol (5.3 mmol, 3 eq.) and heated to 120° C. for 30 min (employing a Biotage Initiator® microwave oven). The reaction mixture was concentrated, the residue partitioned between water and ethyl acetate, the aqueous layer reextracted with ethyl acetate, the combined organic layers dried and concentrated in vacuo to yield 530 mg of the desired product (1.64 mmol, 93% yield), which was used in the subsequent cyclization without further purification steps.

1. customcommercially available or prepared
2. dissolution6,232,320 or WO2005110410) were dissolved in 8 mL 1-propyl alkohol
3. concentrationThe reaction mixture was concentrated
4. customthe residue partitioned between water and ethyl acetate
5. customthe combined organic layers dried
6. concentrationconcentrated in vacuo

ORD record

ord-977b8c4d0f6e42de8cefba356c236e72

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08481539B2