P-Cymene → Proquazone

HRID 426828Notes

Reaction equation

HRID 426828 reaction equation
CC1C=CC(C(C)C)=CC=1.[S].[CH3:12][CH:13]1[CH2:22][C:21]2[N:20]([CH:23]([CH3:25])[CH3:24])[C:19](=[O:26])[N:18]=[C:17]([C:27]3[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=3)[C:16]=2[CH2:15][CH2:14]1>>[CH3:12][C:13]1[CH:22]=[C:21]2[C:16]([C:17]([C:27]3[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=3)=[N:18][C:19](=[O:26])[N:20]2[CH:23]([CH3:25])[CH3:24])=[CH:15][CH:14]=1

Participants

4

Reactant 3

HCID 7463P-Cymene2×HCID 5362487SulfurHCID 20390097HCID 20390097, compound

Product 1

HCID 31508Proquazone

Conditions

Temperature
175 °C

Procedure

A mixture of 200 ml. of p-cymene, 40 g. of ferric oxide and 7 g. of sulfur is heated to reflux (ca. 175° C.), and there is then added thereto dropwise over a period of 40 minutes a hot (130° C.) solution of 28.2 g. of 7-methyl-1-isopropyl-4-phenyl-5,6,7,8-tetrahydro-2(1H)-quinazolinone in 200 mls. of p-cymene. The resulting solution is refluxed for 3.5 hours during which time 1.8 mls. of water are collected in a Dean Stark separator. The reaction solution is then cooled to 28° C. and filtered through a celite pad which is then washed 4 times each with 25 mls. of toluene. The toluene washings are extracted with 50 mls. of 4 N. hydrochloric acid and the p-cymene filtrate is extracted with 350 mls. of 4 N. hydrochloric acid. The acid extracts are combined and extracted with 100 mls. of toluene, and such toluene extracts discarded. The acid solution remaining after such toluene extraction is treated by addition of 350 mls. of toluene and 100 g. of 50% aqueous sodium hydroxide solution. The phases are separated and the toluene phase washed twice each with 100 mls. of water, followed by drying over sodium sulfate, filtering and evaporation in vacuo. The solid residue is crystallized from ethyl acetate to obtain 7-methyl-1-isopropyl-4-phenyl-quinazolin-2(1H)-one, m.p. 139°-141° C.

Workup

  1. additionA mixture of 200 ml
  2. additionis then added
  3. temperatureThe resulting solution is refluxed for 3.5 hours during which time 1.8 mls
  4. customof water are collected in a Dean Stark separator
  5. temperatureThe reaction solution is then cooled to 28° C.
  6. filtrationfiltered through a celite pad which
  7. washis then washed 4 times each with 25 mls
  8. extractionThe toluene washings are extracted with 50 mls
  9. extractionhydrochloric acid and the p-cymene filtrate is extracted with 350 mls
  10. extractionextracted with 100 mls
  11. extractionafter such toluene extraction
  12. additionis treated by addition of 350 mls
  13. customThe phases are separated
  14. washthe toluene phase washed twice each with 100 mls
  15. dry with materialby drying over sodium sulfate
  16. filtrationfiltering
  17. customevaporation in vacuo
  18. customThe solid residue is crystallized from ethyl acetate

Sources & evidence

ORD record
ord-6ae9a77d908643419989ae1559ba956d
Source dataset
uspto-grants-1979_10
Patent number
US04171441

Reaction notes

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