South Dakota State University Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange Electronic Theses and Dissertations 1971 The Chemistry of Some Unusual Carbodiimides Donald Melvin Plautz Follow this and additional works at: https://openprairie.sdstate.edu/etd Part of the Organic Chemistry Commons Recommended Citation Plautz, Donald Melvin, "The Chemistry of Some Unusual Carbodiimides" (1971). Electronic Theses and Dissertations. 5279. https://openprairie.sdstate.edu/etd/5279 This Dissertation - Open Access is brought to you for free and open access by Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For more information, please contact [email protected]. I THE CHEMISTRY OF SOME UNUSUAL CARBODIIMIDF.S BY DONALD MELVIN PLAUTZ A thesis submitted in partial fulfillment of the requirements for the degree, Doctor of Philosophy, Major in Chemistry, South Dakota State University 1971 � UTH AKOTA STATE UNIVERSITY LlBRARY THE CHEMISTRY OF SOME UNUSUAL CARBODIIMIDES This dissertation is approved as a creditable and independent investigation by the candidate for the degree, Doctor of Philosophy, and is acceptable as meeting the dissertation requirements for the degree, but \·rithout implying that the conclusions reached by the candidate are necessarily the conclusions of the major department. ABSTRACT Several �-alkyl-�-(N,N-dialkylamino)carbodiimides, which were found to form dimeric species, were prepared, and the structure of the dimeric species determined. A study of the reaction chemistry of both the monomeric and dimeric carbodiimides led to the conclusion that dimerization occurred via a (-n-2s + r2a) ground-state, symmetry-allowed mechanism, and hat thermal decomposition of the dimeric species occurred via a (-,,.,2s +-ir-2s) excited-state, symmetry-allowed mechanism. Although dialkylphosphoramidates have been shown to be useful intermediates in the preparation of unsaturated organic nitrogen compounds, N-acyl- and N-imino-dialkylphosphorohydrazidates were found to be too 1¥1,stable, forming trialkylphosphates upon distillation, to be of any synthetic value. The preparation of several difunctional and bis-carbodiimides was attempted, but no products were isolated. Based on the side reaction products isolated from the reaction mixtures, it was concluded that the desired carbodiimides did form, but that they were too unstable to be isolated under the reaction conditions used. ACKNOWLEDGEMENTS To Professor William S. Wadsworth, Jr. , without whose guidance and patience this e�deavor could not have been completed. To the faculty and graduate students, whom I have known, who have made my association with S. D. S. U. an unforgettable experience. To the National Science Foundation for its support through two Summer Traineeships. And to my family for their patient endurance during this time. i TABLE OF CONTENTS Page Chapter 1. The Chemi:try of Some rr--Alkyl-�-Dialkylamino­ Carbodiimide - Historical •. •. • . •. • . • • •. •. • . • . • . • • •• • •. •. •. •. •. •. 1 Discussion 6 Chapter 2. The Attempted Preparations of Di-functional and 36 Bis-carbodiimides - Historical and Discussion . • 61 Experimental Section •••••••• . • 61 Description of Instruments Used . • ••61 Description of Chemicals Used . • 62 Preparation of Ethyl-N-tert.-butylcarbamate . ••••.62 Preparation of tert.-Butylisocyanate Preparation of Diethyl-fil-,�-dimethylphosphorohyd.raz- . 63 idate (�) •• •• • •• • • •• • •• • • • •• •• Preparation. - of Diethyl-N-piperidinylphosphorohyd.raz- . 64 idate (21b) • • •• • • •• • •• • • • • •• • •• . • 65 Preparation of Diethyl-N-!!_-butylphosphoramidate •• 65 Preparation of Diethyl-N-cycloJ- hexylphosphoramidate •••••• Preparation of 2-tert.-Butyl-�-(N-:N -dimethylamino)- carbodiimide (2 ) •••••••••••••••••••••• 66 Preparation of rr--tert.-Bu.tyl-�-piperdiny2 lcarbodiimide Preparation of rt--tert.-Octyl-N -(N,N-dimethylamino)- 67 carbodiimide (24) •••••••••••••••••• 68 Preparation of �-tert .-Butyl-� -!!_-butylcarbodiimide •• Preparation of �-tert.-Butyl-rf-cyclohexylcarbodiimide •••• 69 2 Isolation of l,3-Di-(N,N-dimethylamino)- ,4-bis­ (tert.-butylimino)-l,3-diazetidine (22-dime�30) 69 Isolation of l,3-Di-N-piperidinyl-2,4-bis- (tert.­ butylimino)-l,3-diazetidine (23-dimer;.••••••••••• 69 ii 30 •••••••••••••••• � 70 Interconversion of� and 70 Reaction of� with r?--tert.-Butyl-N42-!!_-butylcarbodiimide ••• Reaction of 22 �ith r?--tert.-Butyl-N42-cyclohexylcarbodiimide . 71 • • • • Reaction of 22 with 23 ••••••••••••••••• 71. Preparation of rr--tert.-Butyl-il-benzyldimethylanmroniuin . Chloride Carbodiimide (42) ••••••••••••••• 72 Reaction of 22 with Methyliodide ••••••••••••••• 72 Preparation of 0-Ethyl-r?--tert.-butyl-�-(N,N-dimethylamino)- 3 isou.rea ( 45 ) • • • • • • • • • • • • • • • • • • • • • • • • • 73 Preparationgu of ri1--ter(46)t. -•••••Butyl-�-n-butyl-N:- ••••••••-(N,N-dimethyl­•••• 73 amino) anidine 2 3 Preparation of gu�-tert.-Butyl-N -piperidinyl-N -(N,N­ . dimethylamino) anidine (47) •••••••••••• • • 74 30 . Reaction of with Cyclopentadiene ••••• • •• 74 Reaction of 30 with Cyclohexene •••••••••••••••• 75 Ultraviolet Photolysis of 22 ••••••••••••••••• 75 30 Qualitative Study of the Rate of Formation of from 22 75 (94) . • • . Preparation of Benzoylhydrazide 76 (95) . Preparation of r?--Benzoyl-�-benzalhydrazone1 76 (97) . Preparation of �-Benzoyl-N -methyl-rr2henzalhydrazone • 77 (98) . 77 .· .l Preparation of �-Benzoyl-�-methylhydrazide . Preparation of �-Acetyl-�-methylhydrazide (102) 78 Preparation of il-Formyl-�-methylhydrazide (101) • 79 1 1 Reaction of 0 with Nitrous Acid •••807 9 1 . Reaction of 02 with Nitrous Acid . Preparation of r?--Acetyl-�-methylphosphorohydrazidate (llQ) 80 Preparation of �-Formyl-� -methylphosphorohydrazidat-e (111) • 81 Preparation of Triethylphosphate ••••••••••• 82 ·iii Reaction of 107-residue with Sodium Hydride, then Carbon Dioxide • •• • •• •• •• •• •• •• •• • •• •• • • •• • 82 Reaction of 107-residue with Sodium Hydride, then . Benzaldehyde7• •.• • • •• • • • •• • •• •. • • • Reaction of 107-residue with Sodium Hydride, then . tert.-Butylisocyanate •••••••••••••• . •. .••. • 8483 Preparation of Diethylphosphorohydrazidate Preparation of meta-Nitrobenzaliminodiethyl­ . • ••••85 phosphorohydrazidate (117) ••••••••••• The Attempted Preparation of �-tert.-Butyl-�-meta­ . nitrobenza.liminocarbodiimide••••••••• -.-.- . The Attempted Preparation of �-tert.. -Butyl-benz. alimino-. 86 carbodiimide •••••••• 1 The Attempted Preparation of of N -tert.-Buty1-:rl­ . isopropyliminocarbodiimide ••••••••••. ••••. 87 Preparation of Iminoureas and Iminothiou.reas 88 Preparation of �-tert.-Butyl-�-isopropylimino- urea � • •• •• • •• •• •• • • • • • • •• • • • • • •• 88 Preparation of �-tert.-Butyl-�-isopropyliminothiourea ••••• 88 Preparation of �-Phenyl-if-isopropyliminothiou.rea Preparation of i1--tert.-Octyl-rl-isopropylimino- thiou.rea• • •• • • • •• •• •• • • • •• • • • • • • •• 89 Preparation of bis-Ureas and bis-Thioureas •• • • • • • • •• 89 Preparation of Di-tert.- butyl-bis-urea •••••• ••• 89 Preparation of Di-tert.-butyl-bis-thiourea •••••••••. 90 Preparation of Di-tert.-octyl-bis-urea ••• . •• 90 Preparation of Di-tert.-octyl-bis-thiou.rea . •• 90 Preparation of Diphenyl-�-urea ••••••••••••••. 90 Preparation of Dicyclohexyl-bis-u.rea •• 91 Preparation of Aminoureas and Aminothioureas ••••••••• 91 iv Preparation of �-tert.-Butyl-rf-(N,N-dimethyl- amino)urea ., ., •• • •• • • •• • • • • • •• • • • •• • • 91 Preparation of �-Methyl-rf -( N,N -dimethylamino)u rea •• • • · 92 Preparation.C:f tr"rt-- tert.-Butyl-rf-aminothiourea••••••• 92 Preparation of -Phenyl-rf-(N,N-dimethylam ino)thiourea •• 92 Preparation of r1-Phenyl-�-aminothiourea ••••••••• 92 Preparation of rt°-Cyclohexyl-�-(N,N-dimethylamino)- 93 thiourea •• •• • • •• • • •• • •• • • • •• •• •• • • Preparation of rt"-tert.-Octyl-rf-(N,N. -. dimethylamino)-. •••93 thiourea •• • •• .- •• 93 Identification of All Ureas and Thioureas Prepared • • • Preparation of Iminocarbodiimides and bis-Carbodiimides . from the Respective Ureas••••••••••••••• . ••• • 94 Dehydration Using Phosphorus Pentoxide . • • • • 95 Dehydration Using Thionyl Chloride 96 Dehydration Using E_-Tosyl Chloride ••••••••••••• Preparation of Iminocarbodiimides and bis-Carbodiimides from the Respective Thiou.reas •• • • • • • • •• • • • •• 97 • 98 Reaction of Phenylisocyana�e with 21a . Reaction of Methylisocyanate with 21a . • • 99 Dehydrosulfurization of. �-Phenyl-rf. -(N. ,N-dimethy. lamino). - . 99 thiourea •••••• Literature Cited ••••••••••••••••••••••••• 101 V LIST OF FIGURF.s Page Figure 1. Possible structures and decomposition products . of 22-dimer•••••••••• ••••••••. 10 Figure 2. NMR spectral data for 22•••• •••••• 12 3. 30. Figure Possible pathways for nucleophilic addition to 21 4. 27 Figare Bonding Tland antibonding ,,. orbitals of an ethylene moiety•••••• •••••••• . 27 Figure 5. Combinations of approaching ethylene moieties•• 6. Figure Possible sigma bond combinations from two . 27 ethylene moieties•• ••••••••••• 7. Figare Correlation diagram for the formation of a cyclobutane 29 moiety from two ethylene moieties••••• ••••••• 8. Figure Ground state passage of electrons from cyclobutane 31 bonding orbitals to ethylene bonding orbitals••• · • 9. Figure Orthogonal