Lawesson's reagent → 6-(3-bromophenyl)-4,4-dimethyl-1,4-dihydro-2H-3,1-benzoxazine-2-thione

HRID 2304529Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[CH:20]=[CH:19][C:11]3[NH:12][C:13](=O)[O:14][C:15]([CH3:17])([CH3:16])[C:10]=3[CH:9]=2)[CH:5]=[CH:6][CH:7]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:30])=CC=1>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[CH:20]=[CH:19][C:11]3[NH:12][C:13](=[S:30])[O:14][C:15]([CH3:17])([CH3:16])[C:10]=3[CH:9]=2)[CH:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 110 °C

Procedure

A mixture of 6-(3-bromo-phenyl)-4,4-dimethyl-1,4-dihydro-benzo[d][1,3]oxazin-2-one(3 g, 9.04 mmol) and Lawesson's Reagent (1.83 g, 4,51 mmol) in toluene (30 ml) was heated to 110° C. for 24 hours. The reaction was cooled, the toluene moved removed in vacuo and the residue purified via flash chromatography (silica gel, 20% ethyl acetate/hexane) to give 6-(3-bromophenyl)-4,4-dimethyl-1,4-dihydro-2H-3,1-benzoxazine-2-thione (1.93 g, 61%) as a yellow solid: mp 191-193° C.; 1H-NMR (DMSO-d6) (12.3 (s, 1H), 7.92 (s, 1H), 7.72-7.65 (m, 3H), 7.57-7.54 (m, 1H); 7.45-7.39 (m, 1H), 7.14-7.11 (m, 1H), 1.7 (s, 6H); MS (ES) m/z 347 ([M−H]−, 100%); Anal. Calc. For C16H14BrNOS: C, 55.18; H, 4.05; N, 4.02; Found: C, 55.17; H, 3.93; N, 3.97.

Workup

temperatureThe reaction was cooled
customthe toluene moved removed in vacuo
customthe residue purified via flash chromatography (silica gel, 20% ethyl acetate/hexane)

Sources & evidence

ORD record: ord-6bcb88a51de74ffa83c17b273403544f
Source dataset: uspto-grants-2002_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06436929B1

Reaction notes

Loading…