𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Pseudohalogen chemistry. XI. Some aspects of the chemistry of α-thiocyanato-β-dicarbonyl compounds

✍ Scribed by Elaine F. Atkins; Steven Dabbs; Robert G. Guy; Akbar A. Mahomed; Philip Mountford

Book ID
104203183
Publisher
Elsevier Science
Year
1994
Tongue
French
Weight
907 KB
Volume
50
Category
Article
ISSN
0040-4020

No coin nor oath required. For personal study only.

✦ Synopsis

Enobed a-thioqaua@~dicarbonyl compounds dimerise in ethanol at room temperature to give tautomeric 4,5-disubstiRued Zami~ and 2-xetami&thiazoles by a C-S-C + C-N cyclisation. Tautomerism is due to the unusual 4+dicarbonyl-u-thio) sub&i&W. Compe@ intramolecular cyclisations lead to minor amounts of heterccycles containing the thiazole and /or oxathiole ring systems.

MeCOCHCOMe

SCN

!i CN !! CN 1 2 3 4 We have reinvestigated these reactions using diethyl malonate, acetoacetic ester and acetylacetone systems as models, and now report our results and interpretations.7

RESULT!5 AND DISCUSSION

Treatment of diethyl chloromalonate and ethyl 2-chloro-2-methylacetoacetate with potassium or ammonium thiocyanate in ethanol led smoothly to the expected thiocyanates 5 and 6.2

📜 SIMILAR VOLUMES

Pseudohalogen chemistry. VIII—Substituen
Pseudohalogen chemistry. VIII—Substituent constants (Z) for the thiocyanato group in the estimation of the chemical shifts of vinyl protons in α,β-unsaturated thiocyanates
✍ Robert G. Guy 📂 Article 📅 1988 🏛 John Wiley and Sons 🌐 English ⚖ 188 KB

Substituent constants for the thiocyanato group (q:: = 0.94, ZEN = 0.45 and c:zs = 0.41) have heen derived by an additivity procedure, and shown to reproduce the chemical shifts of vinyl protons in a wide variety of a,fL unsaturated thiocyanates with an accuracy of kO.30 ppm in 94% of the cases stud