Triethylamine → Cyclobutanecarboxylic acid, 2-(3-bromophenyl)hydrazide

Triethylamine (6.90 mL, 49.22 mmol) was added dropwise to a suspension of 3-bromophenylhydrazine hydrochloride (5.00 g, 22.37 mmol) in dichloromethane (60 mL) to give a solution. The mixture was cooled in an ice-salt bath and then cyclobutanecarbonyl chloride (2.68 mL, 23.49 mmol) in dichloromethane (10 mL) was added dropwise at such a rate that the internal temperature did not exceed −10° C. After the addition, the mixture was stirred at −5° C. to −10° C. for 1.5 hours. The cooling bath was removed and the mixture was stirred for a further 2 hours at room temperature. The mixture was evaporated in vacuo and 4% aqueous sodium hydrogen carbonate solution was added. The mixture was filtered and the semi-solid was washed with 4% aqueous sodium hydrogen carbonate solution, water and diethyl ether and dried in vacuo to give the title compound (3.60 g, 60%) as a white solid.

1. customto give a solution
2. temperatureThe mixture was cooled in an ice-salt bath
3. customdid not exceed −10° C
4. additionAfter the addition
5. customThe cooling bath was removed
6. stirringthe mixture was stirred for a further 2 hours at room temperature
7. customThe mixture was evaporated in vacuo and 4% aqueous sodium hydrogen carbonate solution
8. additionwas added
9. filtrationThe mixture was filtered
10. washthe semi-solid was washed with 4% aqueous sodium hydrogen carbonate solution, water and diethyl ether
11. customdried in vacuo

ORD record

ord-342f36b22df941aab92e27b2fddea60e

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08772288B2