3-Amino-p-cresol → HCID 14876455, compound

Participants

Reaction Steps

3-Amino-4-methylphenol (9.84 g; 0.08 mole) and trifluoroethyl tosylate (20.32 g; 0.08 mole) were mixed in a 500 ml round-bottomed flask and the flask purged with nitrogen. A short air condenser was added, the nitrogen stream was slowed and located towards the top of the condenser, and the flask was immersed in an oil bath at 200° C. A temperature in the range of 150°-250° C. is acceptable. After the molten reagents had been swirled to complete mixing, the heating was continued for five hours. The flask was allowed to cool and before the mixture had solidified, it was dispersed and dissolved in 200 ml of chloroform. Over four days a light brown precipitate of the tosylate salt of 3-amino-4-methylphenol appeared which was filtered off and recovered. The chloroform was extracted with 10% aqueous sodium hydroxide and the dark brown aqueous phase was extracted with chloroform 50 ml. Ice and concentrated hydrochloric acid (21 ml) were added to the aqueous phase and the brown oil was extracted into chloroform 100 ml plus 50 ml. The chloroform solution was washed with 1N hydrochloric and the chloroform layer was separated, dried with sodium sulfate, filtered and evaporated to give a brown gum that crystallized over a day 8.0 g (49%). Recrystallization from petroleum ether 60/80 gave white, fluffy needles mp. 64°-65°. NMR (deuterodimethylsulfoxide): δ8.86 (s, 1H, OH); 6.8-5.9 (m, 3H, ring protons) resolved as AB quartet at 6.74 (C-5 CH) and 6.01 (C-6 CH), J=8.0 Hz together with 6.13 (d, 1H, J=1.0 Hz, C-2 CH) which in turn coupled with the high-field half of the AB quartet; 5.33 (t, 1H, J=6.8 Hz, N-H); 4.0-3.7 (m, 2H, CH2) resolved as two quadruplets, JCF3, CH2 =9.6 Hz, JCH2, NH=6.8 Hz; 1.99 (s, 3H, CH3). Anal. calc. for C9H10F3NO: C, 52.68; H, 4.91; N, 6.83. Found: C, 52.58; H, 4.99; N, 6.80.

Provenance & Evidence