Succinic anhydride → 6,7-Diethyl-3,4-dihydronaphthalen-1(2H)-one
Reaction equation
[CH2:1]([C:3]1[CH:4]=[C:5]([CH:13]=[CH:14][C:15]=1[CH2:16][CH3:17])[C:6]([CH2:8][CH2:9][C:10](O)=O)=[O:7])[CH3:2].C(C1C=CC=CC=1CC)C.C1(=O)OC(=O)CC1.C(C1C=C(CCCC(O)=O)C=CC=1CC)C>>[CH2:16]([C:15]1[CH:14]=[C:13]2[C:5](=[CH:4][C:3]=1[CH2:1][CH3:2])[C:6](=[O:7])[CH2:8][CH2:9][CH2:10]2)[CH3:17]Participants
Conditions
- Temperature
- 80 °C
Procedure
3-(3',4'-Diethylbenzoyl) propanoic acid (m.p. 93° C, prepared by the acylation of 1,2-diethyl benzene with succinic anhydride) was catalytically reduced to 4-(3',4'-diethylphenyl) butanoic acid (b.p.0.7 143°-147° C). A mixture of this acid (59g; 0.27 mole) and 85% polyphosphoric acid (450g) was warmed to 80° C with stirring for 30 mins. and worked up as in example 8(a) to yield 48.30g (89%) of 6,7-diethyl-1-tetralone, b.p.0.7 118°-122° C. (Found; C, 82.95; H, 9.21; C14H18O requires; C, 83.12; H, 8.97%). Alternatively 4-(3',4'-diethylphenyl butanoic acid (23.3g; 0.106 mole) may be cyclized by stirring at 100° C with 80% sulphuric acid (115ml) for 1 1/2 hrs. After dilution, extraction into ether and distillation 15.53g (74%) of the tetralone was recovered.
Sources & evidence
- ORD record
- ord-32c854e491d843bd8c524b4cbb9890d6
- Source dataset
- uspto-grants-1977_03
- Patent number
- US04014907
Reaction notes
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