N,1-diphenylmethanimine

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 7.6 g of zinc powder (116 mmol) in 45 ml of isopropyl acetate. After 1.83 ml of trimethylchlorosilane (14.4 mmol) had been added, the mixture was heated to 60° C. for 15 min, then allowed to cool to 55° C. and 16.3 g of undiluted methyl bromoacetate (107 mmol) were subsequently added dropwise within 5 min, and the temperature was maintained at 60° C. by external cooling. The mixture was then stirred at 50° C. for 15 min. After cooling to 5° C., 16.1 g of benzalaniline (89 mmol) dissolved in 10 ml of isopropyl acetate were added and the mixture was heated to 25° C. After the mixture had been stirred at 25° C. for 1 h, it was heated to 40° C. for a further 10 min and then cooled to 5° C. Hydrolysis was then effected using 80 ml of concentrated ammonia solution. After 40 ml of isopropyl acetate had been added, the mixture was heated to 50° C. and precipitate formed went into solution. At this temperature, excess zinc was filtered off and the organic phase removed. The organic phase was then washed at 50° C. with 20 ml of water. After the phase separation, the solvent was distilled off under reduced pressure to give a crude product in a yield of 19.7 g (87% of theory) and a purity of >95% (HPLC). After recrystallization from ethyl acetate, methyl 3-(N-phenylamino)-3-phenylpropionate having a melting point of 110° C. was obtained. At room temperature, a three-neck flask equipped with a reflux condenser to cool to 55° C. the temperature was maintained at 60° C. by external cooling After cooling to 5° C. were added the mixture was heated to 25° C After the mixture had been stirred at 25° C. for 1 h it was heated to 40° C. for a further 10 min cooled to 5° C Hydrolysis the mixture was heated to 50° C. precipitate formed At this temperature, excess zinc was filtered off the organic phase removed The organic phase was then washed at 50° C. with 20 ml of water After the phase separation the solvent was distilled off under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Benzaldehyde (0.20 mole) is treated with aniline (0.20 mole) with vigorous stirring in a 1 l. Erlenmeyer Flask. After 15 mins., 33 cc of 95% ethanol is added and the reaction mixture is stirred vigorously for an additional 5 minutes. The reaction mixture is left standing at room temperature for 10 min.; then it is placed in an ice-bath for 0.5 hrs. The crystals which form are collected, washed with 95% ethanol and air-dried. Recrystallization from 85% ethanol gives N-Benzylideneaniline. m.p. 50°-51.5° C. the reaction mixture is stirred vigorously for an additional 5 minutes The reaction mixture is left standing at room temperature for 10 min. then it is placed in an ice-bath for 0.5 hrs The crystals which form are collected washed with 95% ethanol air-dried Recrystallization from 85% ethanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Benzaldehyde (0.20 mole) is treated with aniline (0.20 mole) with vigorous stirring in a 1 l. Erlenmeyer Flask. After 15 mins., 33 cc of 95% ethanol is added and the reaction mixture is stirred vigorously for an additional 5 minutes. The reaction mixture is left standing at room temperature for 10 min.; then it is placed in an ice-bath for 0.5 hrs. The crystals which form are collected, washed with 95% ethanol and air-dried. Recrystallization from 85% ethanol gives N-Benzylideneaniline. m.p. 50°-51.5° C. the reaction mixture is stirred vigorously for an additional 5 minutes The reaction mixture is left standing at room temperature for 10 min. then it is placed in an ice-bath for 0.5 hrs The crystals which form are collected washed with 95% ethanol air-dried Recrystallization from 85% ethanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Chloro-4-(phenylmethoxy)benzene (2.18 g, 0.010 mol) and N-(phenylmethylene)benzenamine (1.81 g, 0.010 mol) were reacted in Na/DMF (1 g: 50 mL) at 50° C. for 7 hrs. The reaction was followed by HPLC to about 90% conversion. This technique indicated among other things the presence of the title compound, benzyldiphenylamine, and some unknown material in a ratio 65:18:17. Similar aqueous workup as for the preparation of benzyldiphenylamine and chromatography on silica gave 0.50 g of the title compound mp 94-5° C. from methanol (lit mp 97-7.5° C. 70% yield. This material is contaminated with a small amount of diphenylbenzylamine. 1H NMR (200 MHz, CDCl3)δ (assignment): 5.03 (s, 2H, Ph2NCH2Ph), 6.96-7.38 (m, 14H, aromatic). MS [m/e (70 eV, % of base peak)] C19H16ClN 293 (M+., 52.8), 295 (M+. +2, 28.8), 202 (M+. --C7H7+, 22), 167 (C6H4NPh)+., 48.3), 91 (C7H7+, 100). FTIR (CDCl3): 3066, 3033, 1589, 1494, 1454 cm-1.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl-4-(phenylmethoxy)benzene (1.98 g, 0.01 mol) and N-(phenylmethylene)benzenamine (1.81 g, 0.01 mol) were reacted in Na/DMF (1 g: 50 mL) at 75° C. for 30 min. Aqueous work-up, extraction with petroleum ether, 3×100 mL, and chromatography with petroleum ether/ethyl acetate 95:5 afforded a total of 1 g. of solid which by HPLC chromatography contained N,N-diphenyl-benzenemethanamine and the title compound in the ratio (6:94 (51% yield by HPLC). The purer fractions from chromatography on silica were combined and the solvent removed. The residual oil was dissolved in methanol and some petroleum ether. On cooling this crystallized the title compound. Two recrystallizations from methanol gave the title compound (98.1% pure; 36% yield), mp 85-6° C. 1H NMR (200 MHz, CDCl3)δ (assignment): 2.29 (s, 3H, methyl), 4.97 (s, 2H, --NCH2Ph), 6.80-6.97 (m, 3H, aromatic) 7.06-7.27 (d, 4 H, J=1.37 Hz, --NC6H4CH3), 7.14-7.36 (m, 7H, aromatic). MS [m/e (70 eV, % of base peak)] PhCH2N(Ph)(C6H4)CH3 273 (M+., 96.5), 196 (M+. --Ph., 31.7), 182 (M+. --PhCH3., 100), 167 (M+. --PhCH2. --CH3., 81.2), 91 (C7H7+, 98.3). FTIR (CDCl3): 3089, 3064, 3030, 2924, 2864, 1596, 1572, 1512, 1497, 1453 cm-1. Aqueous work-up, extraction with petroleum ether, 3×100 mL, and chromatography with petroleum ether/ethyl acetate 95:5 afforded a total of 1 g

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl-4-(phenylmethoxy)benzene (1.98 g, 0.01 mol) and N-(phenylmethylene)benzenamine (1.81 g, 0.01 mol) were reacted in Na/DMF (1 g: 50 mL) at 75° C. for 30 min. Aqueous work-up, extraction with petroleum ether, 3×100 mL, and chromatography with petroleum ether/ethyl acetate 95:5 afforded a total of 1 g. of solid which by HPLC chromatography contained N,N-diphenyl-benzenemethanamine and the title compound in the ratio (6:94 (51% yield by HPLC). The purer fractions from chromatography on silica were combined and the solvent removed. The residual oil was dissolved in methanol and some petroleum ether. On cooling this crystallized the title compound. Two recrystallizations from methanol gave the title compound (98.1% pure; 36% yield), mp 85-6° C. 1H NMR (200 MHz, CDCl3)δ (assignment): 2.29 (s, 3H, methyl), 4.97 (s, 2H, --NCH2Ph), 6.80-6.97 (m, 3H, aromatic) 7.06-7.27 (d, 4 H, J=1.37 Hz, --NC6H4CH3), 7.14-7.36 (m, 7H, aromatic). MS [m/e (70 eV, % of base peak)] PhCH2N(Ph)(C6H4)CH3 273 (M+., 96.5), 196 (M+. --Ph., 31.7), 182 (M+. --PhCH3., 100), 167 (M+. --PhCH2. --CH3., 81.2), 91 (C7H7+, 98.3). FTIR (CDCl3): 3089, 3064, 3030, 2924, 2864, 1596, 1572, 1512, 1497, 1453 cm-1. Aqueous work-up, extraction with petroleum ether, 3×100 mL, and chromatography with petroleum ether/ethyl acetate 95:5 afforded a total of 1 g

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: As can be seen from Table 3, the electronic properties of the substituents on the phenyl ring of the ketone changed the reduction rate but had less effect on the enantioselectivity (18-33%). An acetophenone substituted in the para position by an electron releasing group, such as 4′-methyl and 4′-methoxy, is reduced more slowly than acetophenone (entries 3, 8 and 9). The chloro substituted acetophenones are all reduced faster, especially for the ortho position (entries 3-7). This trend is opposite to the generally observed trend for Noyori's transfer hydrogenation catalysts in which an ortho-Cl substitution decreases the rate of the reduction (S. Hashiguchi, A. Fujii, J. Takehara, T. Ikariya, R. Noyori, J. Am. Chem. Soc. 1995, 117, 7562). The catalyst (iii) with KOtBu is also efficient for the transfer hydrogenation of propiophenone, 2-acetonaphthone, benzophenone, benzylacetone, benzaldehyde and N-benzylideneaniline (entries 11-15). The hydrogenation of propiophenone gave 1-phenylpropanol in 61% e.e (S) (entry 10). The more difficult ketimine N-phenyl-(1-phenylethylidene)amine (Ph-CMe=N-Ph) was only partially reduced (<5%) after 18 h under the same conditions (entry 16), while cyclohexanone was not hydrogenated (entry 17). Transfer hydrogenation of unsaturated ketones was complicated by some reduction of the C═C double bond (Scheme 2).

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 25 grams (0.138 moles) of N-benzylidene aniline [cas no. 538-51-2, from TCI America] was combined with 24.7 grams (0.138 moles) of gamma-aminopropyltrimethoxysilane [cas no. 13822-56-5, Silquest A-1110 Silane from Crompton Corporation] and 100 grams of xylene. The resulting slurry was warmed to 90° C. for one hour before a vacuum of 20 mm Hg was applied. Distillation of the xylene and aniline resulted in 36 grams (98%) of N-benzylidene aminopropyltrimethoxysilane [cas no. 67674-55-9] by GC analysis. Distillation of the xylene and aniline resulted in 36 grams (98%) of N-benzylidene aminopropyltrimethoxysilane [cas no