3-(3-Bromophenyl)-3-methyloxetane synthesis

Yield:1123172-43-9 69%

Reaction Conditions:

with Ziram;triphenylphosphine;diethylazodicarboxylate in toluene at 20; for 18 h;

Steps:

99A.2 Preparation of the Title Compound:

Preparation of the Title Compound: [1341] 428 mg (1.63 mmol) of triphenylphosphine were added to a solution of 200 mg (0.82 mmol) of the diol prepared above in 5.0 ml of toluene. After 10 min of stirring at RT, 374 mg (1.22 mmol) of ziram (zinc dimethyldithiocarbamate) were added and 284 mg (1.63 mmol) of diethyl azodicarboxylate as a 40% strength solution in toluene were added dropwise. The reaction mixture was then stirred at RT for 18 h. After filtration over Celite, the filtrate was concentrated under reduced pressure. This crude product was combined with those of two further reactions (200 mg and 1.1 g of diol, respectively) and purified by column chromatography on silica gel using the mobile phase hexane/0-10% ethyl acetate. The 700 mg of still impure material obtained in this manner were re-purified in identical fashion together with the material obtained from four further reactions (one reaction of 1.1 g of diol and three reactions of in each case 2.33 g of diol). This gave 5.0 g (69% of theory) of the title compound. [1342] ¹H NMR (400 MHz, DMSO-d₆, δ/ppm): 7.37-7.43 (m, 2H), 7.29 (t, 1H), 7.19-7.24 (m, 1H), 4.74 (d, 2H), 4.48 (d, 2H), 1.57 (s, 3H).

References:

US2013/190290,2013,A1 Location in patent:Paragraph 1340; 1341; 1342