Trifluoroacetic acid → 2,3-Dimethylbenzohydrazide

N′-(2,3-Dimethyl-benzoyl)-hydrazinecarboxylic acid, tert-butyl ester (70.3 g, 266 moles) was placed in to a 500 mL round bottom flask. With gentle stirring, 200 mL of trifluoroacetic acid (296 g, 2.6 moles) was slowly added, resulting in a vigorous evolution of gas. The reaction mixture was then stirred at room temperature for 2 hours. Water (ca. 100 mL) was then added slowly to the mixture. The mixture was slowly added to 1 L of a cold 2 M K2CO3 solution, contained in a 2 L beaker, while stirring slowly (evolution of gas). About 200 mL of a 10% NaOH solution and 250 mL of CH2Cl2 were added. The reaction mixture was transferred to a large separatory funnel and gently shaken (gas evolution). The aqueous phase was extracted with CHCl3 and the extracts dried and evaporated to yield a white solid, which was dried in a 50° C. vacuum oven to yield 31.72 g (73% yield) of 2,3-dimethyl-benzoic acid hydrazide. 1H NMR (CDCl3, 300 MHz) δ (ppm): 7-7.3 (m, 4H), 4.00 (br s, 2H), 2.271 (s, 6H).

1. customresulting in a vigorous evolution of gas
2. stirringwhile stirring slowly (evolution of gas)
3. customThe reaction mixture was transferred to a large separatory funnel
4. stirringgently shaken (gas evolution)
5. extractionThe aqueous phase was extracted with CHCl3
6. customthe extracts dried
7. customevaporated
8. customto yield a white solid, which
9. customwas dried in a 50° C. vacuum oven

ORD record

ord-ed68cfccc7214170b888785030d0d18a

Source dataset

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07456315B2