3,3-difluorocyclobutanone synthesis

Yield:1273564-99-0 39%

Reaction Conditions:

with pyridinium chlorochromate in dichloromethane at 20;

Steps:

3,3-Difluorocyclobutanone (21)
Alcohol 20 (1.66 g, 15.6 mmol) was added to a suspension of PCC (4.37 g, 20.2 mmol) in CH₂Cl₂ (30 mL). The reaction mixture was stirred at r.t. overnight, then Et₂O (60 mL) was added, and the resulting mixture was passed through a silica gel pad to remove the chromium salts. The filtrates were subjected to fractional distillation at atmospheric pressure. Yield: 0.632 g (39%); colorless liquid; bp 87-90°C/1 atm. ¹H NMR (400 MHz, CDCl₃): δ = 3.60 (t, J = 10.1 Hz, 4 H). ¹³C NMR (125 MHz, CDCl₃): δ = 196.7 (t, J = 18.2 Hz), 115.9 (t, J = 271Hz), 58.1 (t, J = 26.5 Hz). ¹⁹F NMR (376 MHz, CDCl₃): δ = -101.7. GSMS (EI): m/z = 91 [CF2=CHC(O)]+, 64 [CF2CH2]+, 57 [C3H2F]+. Anal. Calcd for C4H4F2O: C, 45.29; H, 3.80. Found: C, 45.45; H, 3.71.

References:

Melnykov, Kostiantyn P.;Granat, Dmitriy S.;Volochnyuk, Dmitriy M.;Ryabukhin, Sergey V.;Grygorenko, Oleksandr O. [Synthesis,2018,vol. 50,# 24,art. no. SS-2018-T0427-OP,p. 4949 - 4957]

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