DE588647C - Process for the preparation of condensation products of alkylated cyclic aldehydes with acetaldehyde or acetone or their homologues - Google Patents

Description

It is known that condensation products of methylated cyclohexene aldehydes and low ketones or aldehydes can often have a pleasant odor, especially when the aldehyde group in the cyclohexenaldehyde is two or three Methyl groups are directly adjacent.

It has been found that! Condensations products the simple alkyl derivatives, especially methyl derivatives of cycloheptene aldehydes or cyclooctene aldehydes with acetone or acetaldehyde or their homologues, mostly have a very pleasant odor, even if the aldehyde group the methyl groups or other simple alkyl groups are not directly adjacent. As various of the so accessible new compounds have a clear superiority over analogous ones in terms of smell As shown by derivatives of cyclohexene, this observation is an important technical aspect Effect justified. It should be mentioned, for example, that such synthetic products have become accessible that are odorous with

25. a precious natural product, iron, while all synthetic violet fragrances known to date have an odor that differs from that of iron. It ^: based on known facts, such an odor could not have been foreseen with derivatives of the seven- or eight-membered ring.

example 1

100 gi, i, 7-trimethylcyclohepten- (2) -aldehyde- (3) are dissolved in 200 cm ^{3 of} acetone and left to stand for a few hours with 5 g of sodium amide while cooling with cold water. After neutralization with hydrochloric acid, the excess acetone is distilled off, the residue is taken up in ether and washed with soda solution. The condensation product formed from the components by splitting off water is obtained in the fractional distillation as an ^{oil boiling at 95 to 98 0} (0.2 mm).

Example 2

• 100 gi, i, 6-trimethylcyclohepten- (2) -aldehyde- (3) are dissolved in 200 cm ^{3 of} acetone and mixed with a solution of 5 g of sodium in 75 cm ^{3 of} methyl alcohol. After some time, the mixture is acidified with oxalic acid and, after the solvents have been distilled off, taken up in ether and washed with soda solution. The bp of the condensation product is 93 to 95 ° (0.15 mm).

Example 3

ι, ι, 4-trimethylcyclohepten- (2) -aldehyde- (3)

is condensed with acetone according to the instructions given in Example 1 or 2. The Kp.

of the condensation product obtained is from 98 to 100 ° (0.2 mm).

Example 4

100 gi, i-dimethylcyclohepten- (2) -aldehyde- (3) are dissolved in 200 cm ^{3 of} methyl ethyl ketone and mixed with a solution of 5 g of sodium in 75 cm ^{3 of} methyl alcohol. The work-up was done 2. The Kp corresponding to the example. Of the condensation product was 100 to 103 ⁰ (0.3 mm).

Example

ι, ι, o-Trimethylcyclohepten- (3) -aldehyde- (4) was condensed according to the instructions given in Example 2 with acetone. The bp of the condensation product is 98 to 100 ° (0.2 mm).

Example 6

1,1-dimethylcyclooctene - (2) - aldehyde - (3)

was condensed according to the method described in Example 2 with acetone. The Kp. Des obtained condensation product is 105 to 10 8 ° (0.1 mm).

Example 7

^: ■ ' 100 gi, i, 7-trimethylcyclohepten- (2) -aldehyde- (3) are dissolved in 300 cm ^{3 of} methyl ethyl ketone and saturated with dry HCl gas at 0 °, left to stand ι day in the cold and 1 day at room temperature . It is poured into a lot of water; the oil is separated off and washed with soda solution and water. The condensation product obtained in this way boils at 102 to 104 ⁰ (0.2 mm).

Example 8

A mixture of vapors of 1, i-dimethylcyclohepten- (2) -aldehyde- (3) and ■ of acetone, care being taken that the latter is in excess, is under a pressure of about 12 mm at 250 to 300 ° passed through a pipe in which there is alumina. Fractional distillation of the reaction mixture gives the ^{condensate boiling at 92 to 94 0} (0.25 mm) ^; sation product.

Example 9

The condensation described in Example 1 is carried out while cooling with ice and allowing it to stand for days. The condensation product obtained in this case boils indistinctly from about 95 to 120 ⁰ (0.2 mm) and, according to the analysis of the individual fractions, consists of a mixture of the addition product of acetone with the unsaturated aldehyde and the dehydration product mentioned in Example 2 thereof. You can complete the elimination of water by heating the mixture or the addition product alone with small amounts of a suitable acid-acting product, zB'mit potassium bisulfate or with naphthalene - / - sulfonic acid to about 150 ^0th

Example 10

Modification of the process described in Example 9, where the elimination of water is carried out by passing the vapors of the addition product of acetone to the unsaturated aldehyde under a pressure of about 12 mm at about 250 ^° over a suitable catalyst such as active carbon or alumina.

Example 11

100 gi,!, Ö-trimethylcyclohepten- ^ - aldehyde- (3) and 50 g acetaldehyde are left to stand for a ^{few hours with a solution of 5 g sodium in 300 cm 3} methyl alcohol while cooling with cold water. Work-up was carried out according to the instructions given in Example 2. The bp of the condensation product obtained is from 88 to 90 ^° (0.2 mm).

Example 12

100 g of i, i-dimethylcycloheptene- (2) -aldehyde- (3) are according to that described in Example Ii Method with 50 g propionaldiehyd in reaction. The Kp. Des condensation product obtained at 93 to 95 ° (0.25 mm).

Claims (2)

Patent claims: 1. A process for the preparation of fragrances, characterized in that one alkylated cycloheptene aldehydes or cyclooctene aldehydes with acetaldehyde or acetone or whose homologues condensed. 2. Modification of the method specified in claim 1, characterized in that that the addition products formed in the case of mild condensation are subsequently treated with a dehydrating agent treated.