Benzopyrano[3,4-d]pyridine-2-cyano, carboxamidoximes and carboximidates of the formula ##STR1## wherein R represents -C.ident.N, ##STR2## R.sub.1 is a lower alkyl, R.sub.2 is hydrogen or a lower alkyl and R.sub.3 is a straight or branched alkyl having 1 to 20 carbons, a cycloalkyl-lower alkyl group in which the cycloalkyl group has 3 to 8 carbons or it is an arylalkyl group, and R.sub.4 is a lower alkyl group. The compounds are useful for lowering blood pressure.

This invention relates to 5,5-di-lower alkyl-8-alkyl, cycloalkyl-lower 
alkyl or 
arylalkyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridines. 
More particularly, this invention is concerned with novel 2-substituted 
derivatives of those and 10-alkoxy compounds, processes of producing such 
compounds, intermediates produced in such processes, and the 
pharmacological activities of the compounds. 
According to the present invention there is provided novel 
2-substituted-5,5-di-lower alkyl-8-alkyl, cycloalkyl-lower alkyl or 
arylalkyl-10-hydroxy or lower 
alkoxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridines of the formula 
##STR3## 
wherein R represents -C.ident.N (cyano), 
##STR4## 
(carboxamidoxime) or 
##STR5## 
(carboximidate), R.sub.1 is a lower alkyl such as those having 1 to 6 
carbons including methyl, ethyl and propyl, R.sub.2 is hydrogen or a lower 
alkyl group having 1 to 6 carbons including methyl, ethyl and propyl and 
R.sub.3 is an alkyl which is straight chained or branched such as those 
having 1 to 20 carbons including methyl, ethyl, amyl, hexyl, 2-heptyl, 
n-heptyl, 1,2-dimethylheptyl, 1,1-dimethylheptyl, n-octyl, 2-nonyl, 
2-tetradecyl, n-hexadecyl and 2-eicosanyl, or R.sub.3 is a 
cycloalkyl-lower alkyl group in which the cycloalkyl group has 3 to 8 
carbons and the lower alkyl group has 1 to 6 carbons, including the 
cyclopropylmethyl, cyclopentylethyl, cyclohexylpropyl and cyclooctylbutyl 
groups, or R.sub.3 is an aryl-C.sub.1 to C.sub.10 -alkyl group and 
particularly phenyl-alkyl groups such as benzyl, phenylethyl, 
phenylpropyl, 4-(4-fluorophenyl)-1-methylbutyl, 
4-(4-methylphenyl)-1-methylbutyl and 1,2-dimethyl-7-phenylheptyl and 
R.sub.4 is a lower alkyl group having 1 to 6 carbons such as methyl, ethyl 
and propyl. It is intended to include in phenyl-alkyl groups those groups 
in which the phenyl has 1 to 3 halo groups such as chloro, bromo and 
fluoro, hydroxy, lower alkoxy groups such as methoxy, ethoxy and propoxy, 
nitro and lower alkyl groups such as methyl, ethyl and propyl, and 
trifluoromethyl. Compounds included within the above formula are those in 
which: 
1. R is --C.ident.N, R.sub.1 is methyl and R.sub.2 is hydrogen or methyl. 
2. R is 
##STR6## 
R.sub.1 is methyl and R.sub.2 is hydrogen or methyl. 3. R is 
##STR7## 
4. R is 
##STR8## 
and R.sub.1 is methyl. 5. R is 
##STR9## 
R.sub.1 is methyl and R.sub.2 is hydrogen or methyl. The nomenclature used 
in this specification to identify the compounds is the same as that used 
in many U.S. Pat., as see Nos. 3,991,194; 3,878,219; 3,798,326; 3,787,424; 
3,656,906; 3,576,798 and 3,522,260. The current Chemical Abstracts 
nomenclature, however, differs from that used in this specification. 
Chemical Abstracts names the ring system 
##STR10## 
as 1,3,4,5-tetrahydro-2H-[1] benzopyrano[4,3-c]-pyridine. If that 
nomenclature were followed the compound of Example 1 would be named 
2-Cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-1,3,4,5-tetrahydro-2H-[1]benzo 
pyrano[4,3-c]pyridine-10-ol and the compound of Example 2 would be named 
5,5-dimethyl-8-(1,2-dimethylheptyl)-1,3,4,5-tetrahydro-2H-[1]benzopyrano[4 
,3 -c]pyridine-10-ol-2-carboxamidoxime. 
In the first step of producing the compounds of this invention a previously 
known (see U.S. Pat. Nos. 3,576,798 and 3,932,432) 5,5-di-lower 
alkyl-8-alkyl, cycloalkyl-lower alkyl or 
arylalkyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1] benzopyrano[3,4-d]pyridine 
is reacted with a reactive cyanogen halide, such as cyanogen bromide, to 
produce a 2-cyano-5,5-di-lower alkyl-8-alkyl, cycloalkyl-lower alkyl or 
arylalkyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridine. 
This process step may be illustrated as follows: 
##STR11## 
wherein R.sub.1 and R.sub.3 have the previously assigned meaning and X is 
a reactive halo ion and particularly is bromo or chloro. 
The described reaction is readily effected by combining the reactants in a 
suitable liquid reaction medium and advisably a medium in which the 
reactants are soluble, such as a lower alcohol like methanol. The reaction 
proceeds to completion in a few hours or less at a temperature from about 
0.degree. to 30.degree. C. Following termination of the reaction the 
desired product can be readily isolated from the reaction mixture by 
conventional separation procedures. 
Some of the 2-cyano derivatives which are produced as described are 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-8-(2-heptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benz 
opyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-10-hydroxy-8-(1-pentyl)-1,2,3,4-tetrahydro-5H-[1]benz 
opyrano [3,4-d]pyridine, 
2-cyano-8-(1-cyclohexylethyl)-5,5-dimethyl-10-hydroxy-1,2,3,4-tetrahydro-5 
H-[1]benzopyrano[3,4-d]pyridine, 
2-cyano-8-(3-cyclopentylpropyl)-5,5-dimethyl-10-hydroxy-1,2,3,4-tetrahydro 
-5H-[1]benzopyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-8-[4-(4-fluorophenyl)-1-methylbutyl]-10-hydroxy-1,2,3 
,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-8-[4-(4-methylphenyl)-1-methylbutyl]-10-hydroxy-1,2,3 
,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridine and 
2-cyano-5,5-dimethyl-8-(1,2-dimethyl-7-phenylheptyl)- 
10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridine. 
The 2-cyano-5,5-di-lower alkyl-8-alkyl, cycloalkyl-lower alkyl or 
arylalkyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridines 
can be readily etherified or converted to the otherwise corresponding 
10-lower alkoxy compound by reacting the 10-hydroxy compound with a 
reactive halo lower alkane such as iodomethane, bromoethane or 
iodopropane. The reaction is readily effected by combining the reactants 
in an anhydrous liquid reaction medium such as acetone in the presence of 
a hydrohalide binding material, such as sodium carbonate. An elevated 
temperature, such as the reflux temperature, serves to promote the 
reaction and bring it to completion more quickly. Following the reaction 
the desired product can be isolated from the reaction mixture by 
conventional procedures. 
Among the ethers which can be produced as described are 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-10-ethoxy-8-(2-heptyl)-1,2,3,4-tetrahydro-5H-[1]benzo 
pyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-8-(1-pentyl)-10-propoxy-1,2,3,4-tetrahydro-5H-[1]benz 
opyrano [3,4-d]pyridine, 
2-cyano-10-butoxy-8-(1-cyclohexylethyl)-5,5-dimethyl-1,2,3,4-tetrahydro-5H 
-[1]benzopyrano[3,4-d] pyridine, 
2-cyano-8-(3-cyclopentylpropyl)-5,5-dimethyl-10-pentoxy-1,2,3,4-tetrahydro 
-5H-[1]benzopyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-8-[4-(4-fluorophenyl)-1-methylbutyl]-10-methoxy-1,2,3 
,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridine, 
2-cyano-5,5-dimethyl-10-ethoxy-8-[4-(4-methylphenyl)-1-methylbutyl]-1,2,3, 
4-tetrahydro-5H-[1]benzopyrano[3,4-d] pyridine and 
2-cyano-5,5-dimethyl-8-(1,2-dimethyl-7-phenyl-heptyl)-10-propoxy- 
1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridine. 
The already described 2-cyano compounds, whether they have a 10-hydroxy or 
10-lower alkoxy substituent, can be converted to the otherwise 
corresponding 2-carboxamidoximes by reaction with hydroxylamine in a 
suitable liquid reaction medium, such as dimethylformamide, at a 
moderately elevated temperature. The process can be illustrated as 
follows: 
##STR12## 
wherein R.sub.1, R.sub.2 and R.sub.3 have the previously assigned 
significance. The reaction proceeds to essential completion in 1 to 2 
hours after which the product can be separated from the reaction mixture. 
Among the compounds produced in the described manner are 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]be 
nzopyrano[3,4-d]pyridine-2-carboxamidoxime, 
5,5-dimethyl-8-(2-heptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[ 
3,4-d]pyridine-2-carboxamidoxime, 
5,5-dimethyl-10-hydroxy-8-(1-pentyl)-1,2,3,4-tetrahydro-5H-[1]benzopyrano[ 
3,4-d]pyridine-2-carboxamidoxime, 
8-(1-cyclohexylethyl)-5,5-dimethyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]ben 
zopyrano[3,4-d]pyridine-2-carboxamidoxime, 
8-(3-cyclopentylpropyl)-5,5-dimethyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]b 
enzopyrano[3,4-d]pyridine-2-carboxamidoxime, 
5,5-dimethyl-8-[4-(4-fluorophenyl)-1-methylbutyl]-10-hydroxy-1,2,3,4-tetra 
hydro-5H-[1]benzopyrano [3,4-d]pyridine-2-carboxamidoxime, 
5,5-dimethyl-8-[4-(4-methylphenyl)-1-methylbutyl]-10-hydroxy-1,2,3,4-tetra 
hydro-5H-[1]benzopyrano[3,4-d]pyridine-2-carboxamidoxime and 
5,5-dimethyl-8-(1,2-dimethyl-7-phenylheptyl)-10-hydroxy-1,2,3,4-tetrahydro 
-5H-[ 1]benzopyrano[3,4-d]pyridine-2-carboxamidoxime and the corresponding 
compounds in which a 10-methoxy, ethoxy, propoxy, butoxy or pentoxy group 
is present in place of the 10-hydroxy group. 
The 2-cyano-5,5-di-lower alkyl-8-alkyl, cycloalkyl-lower alkyl or 
arylalkyl-10-hydroxy or lower 
alkoxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridines upon reaction 
with an alkali metal lower alkoxide yield the otherwise corresponding 
lower alkyl 2-carboximidates. This process can be represented as follows: 
##STR13## 
wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 have the previously assigned 
significance, and Y is a reactive alkali metal such as sodium, potassium 
or lithium. Some of the alkali metal lower alkoxides which can be used in 
the process are sodium methoxide, potassium ethoxide and lithium 
propoxide. The reaction is readily effected in an alcohol such as methanol 
at ambient temperature in about 1 to 3 hours. Following termination of the 
reaction the desired product can be isolated from the reaction mixture by 
conventional procedures. In this regard, when R.sub.2 is hydrogen in the 
starting material the phenol or hydroxy group is converted to an 
intermediate alkali metal salt which, however, is readily reconverted to 
the phenol group by use of a mild acid. 
Among the lower alkyl 2-carboximidates produced as described are methyl 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]be 
nzopyrano[3,4-d]pyridine-2-carboximidate, methyl 
5,5-dimethyl-8(2-heptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benzopyrano[3 
,4-d]pyridine-2-carboximidate, ethyl 
5,5-dimethyl-10-hydroxy-8-(1-pentyl)-1,2,3,4-tetrahydro-5H-[1]benzopyrano[ 
3,4-d]pyridine-2-carboximidate, methyl 
8-(1-cyclohexylethyl)-5,5-dimethyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]ben 
zopyrano[3,4-d]pyridine-2-carboximidate, ethyl 
8-(3-cyclopentylpropyl)-5,5-dimethyl-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]b 
enzopyrano[3,4-d] pyridine-2-carboximidate, propyl 
5,5-dimethyl-8-[4-(4-fluorophenyl)-1-methylbutyl]-10-hydroxy-1,2,3,4-tetra 
hydro-5H-[1]benzopyrano[3,4-d]pyridine-2-carboximidate, methyl 
5,5-dimethyl-8-[4-(4-methylphenyl)-1-methylbutyl]-10-hydroxy-1,2,3,4-tetra 
hydro-5H-[1]benzopyrano[3,4-d]pyridine-2-carboximidate and ethyl 
5,5-dimethyl-8-( 
1,2-dimethyl-7-phenylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]benzopyra 
no [3,4-d]pyridine-2-carboximidate and the corresponding compounds in which 
a 10-methoxy, ethoxy, propoxy, butoxy and pentoxy group is present in 
place of the 10-hydroxy group. 
In all of the compounds named previously in this specification the 
5,5-dimethyl substituents can be replaced with 5,5-diethyl, 5,5-dipropyl 
and other lower alkyl groups to the extent such substitution is not 
prevented by steric hindrance. 
The compounds of this invention, having a basic nitrogen atom, readily form 
acid addition salts with inorganic acids and organic acids such as 
hydrochloric acid, sulfuric acid, phosphoric acid, citric acid, acetic 
acid, maleic acid and oxalic acid. 
The compounds of this invention, as a base or nontoxic acid addition salt, 
in which R is carboxamidoxime or is a carboximidate group and R.sub.2 is 
hydrogen or lower alkyl, when administered to a mammal parenterally or 
orally exert an anti-hypertensive effect. The compounds thus can be used 
to reduce blood pressure. 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]ben 
zopyrano[3,4-d]pyridine-2-carboxamidoxime administered intraperitoneally to 
anesthetized hypertensive rats at 10 and 20 mg/kg lowered the mean 
arterial blood pressure about 46 to 60% in the first one-half hour after 
administration and the blood pressure remained depressed for at least 2 
hours. The same compound at 10 and 20 mg/kg administered intraperitoneally 
to unanesthetized hypertensive rats lowered systolic blood pressure 16 to 
39% in about 2 hours. A 10 mg/kg dose of the compound in unanesthetized 
normotensive rats lowered the systolic blood pressure about 25% in about 
2.25 hours. 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro-5H-[1]ben 
zopyrano[3,4-d]pyridine-2-carboxamidoxime administered intraperitoneally to 
anesthetized hypertensive rats at doses of 1 to 17 mg/kg lowered the mean 
arterial blood pressure 33 to 68% in thirty to forty-five minutes or less. 
The same compound at 5 to 20 mg/kg administered intraperitoneally to 
unanesthetized hypertensive rats lowered systolic blood pressure 14 to 68% 
in one-half hour to one hour or less. Dosages of 1 to 10 mg/kg 
intraperitoneally of the compound in anesthetized normotensive rats 
lowered the mean arterial blood pressure about 30 to 67% in one-half hour 
to two hours. 
Methyl 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro-5H-[1]be 
nzopyrano[3,4-d]pyridine-2-carboximidate at dosages of 0.5 to 10 mg/kg 
intraperitoneally in unanesthetized normotensive rats lowered systolic 
blood pressure 10 to 32% in less than one-half hour with dosages of 2 
mg/kg and less and giving results as good as higher dosages. 
The amount of active ingredient administered may be varied; however, it is 
necessary that the amount of active ingredient be such that a suitable 
dosage is given. The selected dosage depends upon the desired therapeutic 
effect and on the duration of treatment. Dosages of from 0.01 to 25 mg/kg 
of body weight daily, preferably in divided doses, i.e., three to four 
times daily, can be administered. 
The active agents of this invention can be administered to animals, 
including humans, as pure compounds. It is advisable, however, to first 
combine one or more of the compounds with a suitable pharmaceutical 
carrier to attain a satisfactory size to dosage relationship and thereby 
obtain a pharmaceutical composition. 
Pharmaceutical carriers which are liquid or solid can be used. Solid 
carriers such as starch, sugar, talc and the like can be used to form 
powders. The powders can be used for direct administration or they may be 
used to make tablets or to fill gelatin capsules. Suitable lubricants like 
magnesium stearate, binders such as gelatin, and disintegrating agents 
like sodium carbonate in combination with citric acid can be used to form 
tablets. Sweetening and flavoring agents can also be included. 
Unit dosage forms such as tablets and capsules can contain any suitable 
predetermined amount of one or more of the active agents, and they may be 
administered one or more at a time at regular intervals. Such unit dosage 
forms, however, should generally contain a concentration of 0.1 to 50 
percent by weight of one or more of the active compounds. Unit dosage 
forms, such as tablets and capsules, can contain about 2 to 300 mg of 
active agent. 
A typical tablet can have the composition: 
______________________________________ 
Mg 
______________________________________ 
Active agent (1) 100 
Starch U.S.P. 57 
Lactose U.S.P. 73 
Talc, U.S.P. 9 
Stearic acid 12 
______________________________________ 
(1) 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]b 
nzopyrano[3,4-d]pyridine-2-carboxamidoxime 
The compounds exhibit both oral and parenteral activity and accordingly 
they can be formulated in dosage forms for either oral or parenteral 
administration to a patient. 
Solid dosage forms for oral administration include capsules, tablets, 
pills, powders, granules and the like. 
Liquid dosage forms for oral administration include emulsions, solutions, 
suspensions, syrups and the like, containing diluents commonly used in the 
art, such as water. Besides inert diluents, such preparations can also 
include adjuvants such as wetting agents, emulsifying and suspending 
agents and sweetening, flavoring and perfuming agents. 
Preparations for parenteral administration include sterile aqueous or 
non-aqueous solutions. Examples of non-aqueous solvents or vehicles are 
propylene glycol, polyethylene glycol, vegetable oils such as olive oil 
and injectable organic esters such as ethyl oleate. The parenteral 
preparations are sterilized by conventional methods. 
The following examples are presented to further illustrate the invention.

EXAMPLE 1 
2-Cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5 
H-[1]benzopyrano[3,4-d]pyridine 
A mixture of 4.6 g (0.0129 mole) of 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1] 
benzopyrano[3,4-d]pyridine, 1.38 g (0.013 mole) of cyanogen bromide, 2.13 
g (0.026 mole) of sodium acetate and 35 ml of methanol was stirred at 
0.degree. C for 3 hours, and then at ambient temperature for 12 hours. 
After removal of the solvent under reduced pressure, water was added to 
the residue and the mixture was extracted with diethyl ether. The organic 
layer was washed with 2 N HCl, followed by saturated NaCl solution. The 
ether layer was separated, dried over Na.sub.2 SO.sub.4 and concentrated 
to give 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine as a yellow oil (4.9 g, 99% yield) which 
crystallized upon standing. 
Anal. Calcd. for C.sub.24 H.sub.34 N.sub.2 O.sub.2 : C, 75.35; H, 8.96; N, 
7.32. Found: C, 75.19; H, 8,89; N, 7.14. 
EXAMPLE 2 
5,5-Dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]ben 
zopyrano[3,4-d]pyridine-2-carboxamidoxime 
A mixture of 0.5 g (1.31 mmole) of 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine, 0.139 g (2.0 mmole) of hydroxylamine 
hydrochloride and 0.212 g (2.0 mmole) of sodium carbonate in 17 ml of 
dimethylformamide was heated on a steam bath for 1.5 hours. After cooling, 
the reaction mixture was partitioned between 50 ml each of chloroform and 
water. The organic layer was separated, washed with water, dried over 
Na.sub.2 SO.sub.4 and filtered. After removal of the solvents on a rotary 
evaporator, the last traces of dimethylformamide were removed in vacuo. 
Crystallization from chloroform gave 280 mg (56%) of 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro-5H-[1]be 
nzopyrano[3,4-d]pyridine-2-carboxamidoxime as colorless crystals. 
Recrystallization of the compound from chloroform gave poor recovery 
(17.5%) of the crystalline material, m.p. 142.degree.-45.degree. C. The 
assigned structure was confirmed by the ir, nmr and mass spectra (M.sup.+ 
at 415). Thin-layer chromatography (20% methanol/chloroform on silica gel) 
revealed two spots corresponding to the two stereoisomers. 
EXAMPLE 3 
2-Cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro-5 
H-[1]benzopyrano[3,4-d]pyridine 
A mixture of 2.3 g (0.006 mole) of 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-hydroxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine, 2.8 g (0.02 mole) of iodomethane and 10 g 
(0.0725 mole) of potassium carbonate in anhydrous acetone was heated at 
reflux, with stirring, for 7 hours. After cooling, the solid was removed 
by filtration and discarded, and the mother liquor was concentrated on a 
rotary evaporator. The residual material was taken up in diethyl ether (70 
ml) and washed with water, 1N HCl, and again with water. The organic layer 
was dried over sodium sulfate, filtered and concentrated to give 1.84 g 
(78%) of 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine as a yellow oil. The ir and nmr spectra 
confirmed the structure. The compound appeared pure by thin-layer 
chromatography (silica gel, chloroform solvent system). 
EXAMPLE 4 
5,5-Dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4 
-tetrahydro-5H-[1]benzopyrano[3,4-d]pyridine-2-carboxamidoxime 
A mixture of 238 mg (0.6 mmole) of 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine, 69.5 mg (1.0 mmole) of hydroxylamine 
hydrochloride and 106 mg (1.0 mmole) of sodium carbonate in 7 ml of 
dimethylformamide was heated on a steam bath for 2.5 hours. The progress 
of the reaction was monitored by tlc (silica gel, 5% MeOH/CHCl.sub.3). 
After cooling, 70 ml of chloroform was added and the mixture was 
extracted with water (2 .times. 75 ml). The organic layer was separated, 
dried over Na.sub.2 SO.sub.4, filtered and concentrated to give a residue 
which crystallized from chloroform/hexane to give 120 mg (47%) of 
colorless solid 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro-5H-[1]be 
nzopyrano[3,4-d]pyridine-2-carboxamidoxime, m.p. 173.degree.-76.degree. C. 
The ir, nmr and mass spectra (M.sup.+ at 429) confirmed the structure. The 
reaction was repeated on a larger scale to give 18% of the desired 
product, m.p. 176.degree.-78.degree. C. 
Anal. Calcd. for C.sub.25 H.sub.39 N.sub.3 O.sub.3 : C, 69.93; H, 9.09; N, 
9.79. Found: C, 69.61; H, 9.16; N, 9.75. 
EXAMPLE 5 
Methyl 
5,5-Dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro-5H-[1]be 
nzopyrano[3,4-d]pyridine-2-carboximidate 
A mixture of 198 mg (0.5 mmole) of 
2-cyano-5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro- 
5H-[1]benzopyrano[3,4-d]pyridine and 2.7 mg (0.05 mmole) of sodium 
methoxide in 8 ml of methanol was refluxed with stirring for 3 hours and 
allowed to stir overnight at ambient temperature. Ammonium chloride (29.4 
mg; 0.55 mmole) was added and the stirring was continued for an additional 
2 hours. The reaction mixture was concentrated on a rotary evaporator to 
give a residue to which was added 1 ml of diethyl ether. The solid was 
collected by filtration to give 138 mg in two crops (59%) of methyl 
5,5-dimethyl-8-(1,2-dimethylheptyl)-10-methoxy-1,2,3,4-tetrahydro-5H-[1]be 
nzopyrano[3,4-d]pyridine-2-carboximidate as a light yellow solid, m.p. 
134.degree.-36.degree. C. The ir and nmr spectra confirmed the structure. 
Anal. Calcd. for C.sub.26 H.sub.40 N.sub.2 O.sub.3.CH.sub.3 OH: C, 70.40; 
H, 9.62; N, 6.08. Found: C, 70.82; H, 9.12; N, 6.16. 
The foregoing detailed description has been given for clearness of 
understanding only, and no unnecessary limitations should be understood 
therefrom, as modifications will be obvious to those skilled in the art.