2-BroMo-5,5-diMethylcyclohex-1-enecarbaldehyde synthesis

Yield:-

Reaction Conditions:

with phosphorus tribromide in N,N-dimethyl-formamide at 0 - 60;

Steps:

1.3.A Step A: Synthesis of 2-Bromo-5,5-dimethylcyclohex-1 -ene-1 -carbaldehyde (3.2)

To a solution of 4,4-dimethylcyclohexanone (50.40 g, 399.37 mmol) in PBr3 (103.07 mL) was added DMF (88.34 mL) at 0 00 The mixture was stirred for 20 mm and then PBr3 (103.07 mL) was added at 0 00 The reaction mixture was stirred at the same temperature for 10 mm and then heated at 60 00 overnight. The mixture was then poured into ice water (1 L), and the resulting mixture was extracted with DCM (3x500mL). The combined organic phases were dried over anhydrous Na2504, filtered and concentrated to afford crude 3.2 (65.50 g, 301 .70 mmol, 76% yield), which was used in the next step without further purification. 1H NMR (400 M, ODd3), ? 10.03 (s, 1H), 2.76 (m, 2H), 2.09 (m, 2H), 1.54(m, 2H), 0.95 (s, 6H).

References:

WO2017/101851,2017,A1 Location in patent:Paragraph 0140; 0141