Hydrochloric Acid → Ethyl 5-amino-2-methylthiazole-4-carboxylate

HRID 131347Notes

Reaction equation

HRID 131347 reaction equation
[C:1]([NH:4][CH:5]([C:9]#[N:10])[C:6]([O-:8])=[O:7])(=O)[CH3:2].[C:11]1([CH3:17])C=CC=CC=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:27])=CC=1.Cl>CO>[CH2:11]([O:8][C:6]([C:5]1[N:4]=[C:1]([CH3:2])[S:27][C:9]=1[NH2:10])=[O:7])[CH3:17]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 1140Toluene2×HCID 87949Lawesson's reagentHCID 18981579HCID 18981579, compound

Product 1

HCID 13329095Ethyl 5-amino-2-methylthiazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
70 °C

Procedure

Add acetoamidocyanoacetate (1000 g, 5.88 mol) to a 22 L 3-necked RB flask equipped with reflux condenser, thermometer, mechanical stirrer then add toluene (12L). Add to this suspension at RT Lawesson's reagent (1187 g, 2.93 mol). Stir the resulting yellow slurry at 70° C. for 16 h, cool to RT. Pour the top yellow solution away from the gummy material on the bottom of the flask into a separation funnel. Add 1N HCl solution (2.5L) and TBEA (2.5L) and stir the mixture. After 15 min., combine the bi-phase solution was into the toluene solution in the funnel. Gummy material maybe left in the flask. Repeat the above procedure again. Separate the aqueous and wash the combine organic solution with 1N HCl (2×2.5L). Separate the organic layer and combine the aqueous and basify with 2N KOH solution. Add ethyl acetate (3×4L) and extract the product. Combine the organic layer, dry over anhydrous sodium sulfate, and evaporate to give 552 g as a pale yellow solid. Dissolve the remaining gummy in methanol (1L) and evaporate to dryness. Add MTBE (2.5L) and 1N HCl (4 L) and stir the mixture. After 15 min., separate the organic layer and basify the aqueous with 2N KOH solution Extract the product with ethyl acetate (2×2L). Combine the organic layers and dry over anhydrous sodium sulfate and evaporate to give 165 g as a pale yellow solid. (Total: 717 g, 65%). Mass spectrum (m/e): 187(M+1); 1HNMR(300 MHz, DMSO-d6, ppm): δ 1.21(t, 3H), 2.38(s, 3H), 4.21(q, 2H), 7.21(bs, 2H). 13CNMR(75 MHz, DMSO, ppm): δ 15.1, 19.2, 59.8, 119.3, 145.6, 161.7, 164.1. Formula: C7H10N2O2S.

Workup

  1. customequipped
  2. temperaturewith reflux condenser
  3. temperaturecool to RT
  4. additionPour the top yellow solution away from the gummy material on the bottom of the flask into a separation funnel
  5. stirringstir the mixture
  6. waitAfter 15 min.
  7. waitGummy material maybe left in the flask
  8. customSeparate the aqueous and
  9. washwash the combine organic solution with 1N HCl (2×2.5L)
  10. customSeparate the organic layer
  11. extractionAdd ethyl acetate (3×4L) and extract the product
  12. dry with materialCombine the organic layer, dry over anhydrous sodium sulfate
  13. customevaporate
  14. customto give 552 g as a pale yellow solid
  15. customevaporate to dryness
  16. stirringAdd MTBE (2.5L) and 1N HCl (4 L) and stir the mixture
  17. waitAfter 15 min.
  18. customseparate the organic layer
  19. extractionExtract the product with ethyl acetate (2×2L)
  20. dry with materialCombine the organic layers and dry over anhydrous sodium sulfate
  21. customevaporate
  22. customto give 165 g as a pale yellow solid

Sources & evidence

ORD record
ord-4bff23d136404f198ac4d992a59147cd
Source dataset
uspto-grants-2008_06
Patent number
US07384934B2

Reaction notes

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