Diethyl Phenyl Orthoformate1

[14444-77-0]  · C11H16O3  · Diethyl Phenyl Orthoformate  · (MW 196.25)

(mixed orthoformate which undergoes monosubstitution with Grignard reagents and other organometallic reagents to give diethyl acetals)

Alternate Name: diethoxy(phenoxy)methane.

Physical Data: bp 112 °C/13 mmHg; n20D 1.4799; d 1.016 g cm-3

Solubility: insol cold H2O; sol most organic solvents.

Analysis of Reagent Purity: 1H NMR.2

Form Supplied in: colorless liquid; widely available.

Handling, Storage, and Precautions: store in absence of water. Possibility of hydrolysis and disproportionation.2 Irritates eyes, skin, and lungs. Use in a fume hood.

Diethoxymethylation.

The reagent reacts with various nucleophiles, especially Grignard reagents (RMgX) under mild conditions, and gives good yields of the homologous aldehyde diethyl acetals (eq 1).3

Owing to the lack of reviews, the scope of the reaction is best shown by grouping the possible Grignard reagents: alkyl-MgX;3-5 alkenyl-MgX (other than allyl);6 allyl-MgX (allyl rearrangements possible);4,7 vinyl-MgX;4 cycloalkadienylmethyl-MgX;8 alkynyl- or alkynylalkyl-MgX (an important group);4,9 aryl-MgX;3,10 1-phenyl-1-ethyl-MgX;11 3-quinolizidinemethyl-MgX;12 bullvalenyl-MgX;13 arylsulfonylchloromethyl-MgX;14 Bu3Sn-MgX (important source of various organotin reagents);15 t-butylMgX does not react.4 Propargylorgano-Al, -Mg, and -Zn derivatives (propargyl-allene rearrangements) react analogously,16 as do some cyclic organolithium compounds,17 a dilithiocarborane,18 some organozinc ester enolates,4 and cyclohexanone magnesium enolate.4

Related Reagents.

Simple orthoformates like Triethyl Orthoformate react analogously,19 but yields are generally low. Ethyl diphenyl orthoformate reacts with 2 equiv of Phenylmagnesium Bromide to give ethylbenzhydryl ether in 87% yield.3

See also Carbon Monoxide; N,N-Dimethylformamide; 1,1,3,3-Tetramethylbutyl Isocyanide; Triethyl Orthoformate.


1. (a) Fieser, L. F.; Fieser, M. FF 1972, 3, 97. (b) Beilstein 1978, 6(IV), 610.
2. (a) Scheeren, J. W.; Stevens, W. RTC 1969, 88, 897. (b) Hydrolysis: Anderson, E.; Fife, T. H. JOC 1972, 37, 1993.
3. Stetter, H.; Reske, E. CB 1970, 103, 643.
4. (a) Barbot, F.; Poncini, L.; Randrianoelina, B.; Miginiac, P. JCR(S) 1981, 343 and JCR(M) 1981, 4016. (b) Barbot, F.; Miginiac, P. BSF(2) 1983, 41.
5. (a) Stetter, H.; Steinbeck, K. LA 1974, 1315. (b) Willy, E. W.; McKean, D. R.; Garcia, B. A. BCJ 1976, 49, 1989.
6. (a) Stetter, H.; Kuhlmann, H. S 1975, 379. (b) Bishop, C. E.; Morrow, G. W. JOC 1983, 657 (footnote 12).
7. (a) Botteghi, C.; Caccia, C.; Chelucci, G.; Soccolini, F. JOC 1984, 49, 4290. (b) Caccia, C.; Chelucci, G.; Botteghi, C. SC 1981, 11, 71. (c) Duhamel, L.; Ancel, J.-E. T 1992, 48, 9237. (d) Oida, T.; Tanimoto, Sh.; Terao, H.; Okano, M. JCS(P1) 1986, 1715.
8. Scholz, D.; Schmidt, U. CB 1974, 107, 2295.
9. Poncini, L. LA 1984, 1529. (b) Poncini, L. JOC 1984, 49, 2031. (c) Gorgues, A.; Stephan, D.; Belyasmine, A.; Khanous, A.; Le Coq A. T 1990, 46, 2817.
10. (a) Cresp, T. M.; Giles, R. G. F.; Sargent, M. V.; Brown, C.; Smith, D. O'N. JCS(P1) 1974, 2435. (b) Ando, M.; Emoto, S. BCJ 1978, 51, 2437.
11. Barbot, F.; Miginiac, Ph. S 1983, 651.
12. Boido-Canu, C.; Boido, V.; Sparatore, F.; Sparatore, A. FES 1988, 43, 801.
13. Zeiger, R.; Sarma, K.; Schröder, G. CB 1986, 119, 2889.
14. Stetter, H.; Steinbeck, K. LA 1972, 766, 89.
15. (a) Quintard, J. P.; Elissondo, B.; Pereyre, M. JOM 1981, 212, C31. (b) Quintard, J. P.; Elissondo, B.; Pereyre, M. JOC 1983, 48, 1559. (c) Duchene, A.; Mouko-Mpegna, D.; Quintard, J. P. BSF(1) 1985, 787.
16. (a) Barbot, F.; Miginiac, Ph. JOM 1992, 440, 249. (b) Stoller, A.; Mioskowski, C.; Sepulchre, C.; Bellamy, F. TL 1990, 31, 361.
17. (a) Carnmalm, B.; Johansson, L.; Rämsby, S.; Stjernström, N. E. ACS 1979, B33, 100. (b) Böhme, H.; Sutoyo, P. N. LA 1982, 1643.
18. Rabilloud, G.; Sillion, B. JOM 1979, 182, 275.
19. Bachman, G. B. OSC 1943, 2, 323.

Heinrich Kuhlmann

RWTH Aachen, Germany



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